Play !
Down under you find a list of very hard sudoku puzzles. You can copy a puzzle from the screen and paste it into the dropbox of the app. You can solve up each puzzle using the "Apply logic" button until the 6 basic sudoku rules don't give any progress anymore. At this point you must find the advanced technique to break the puzzle. It can be a simple swordfish, but it can also be a complex grouped continuous nice loop or a sue de coq. When you have applied such a technique you can use "Apply logic" again. Good luck!
Sudoku puzzles:
<![CDATA[**** PUZZLE OF THE WEEK ****
..1.....7...89..........6..26..3.......5...749...........1.4.5.83.............2..
Demo for video about How to use the Sudoku Explorer:
..45......1..9.5.......2.18.329.....1..2.7..3.....165.72.6.......8.2..7......43..
Skyscraper: 3 in r1c6,r3c1 (connected by r8c16) => r3c45<>3
FISHES
X-Wing
.1............2..42.34..6....596..8..38...19..2..783....4..59.89..3............7.
X-Wing: 1 r27 c58 => r3c58,r9c5<>1
1..7....37....2....59.......9..2.54...4.9.1...12.3..8.......87....8....58....3..6
* X-Wing: 2 r38 c18 => r19c8,r7c1<>2
7....36.8.....24..643........4...8623...5...4261...5........185..73.....8.94....6
X-Wing: 7 r26 c59 => r3c9<>7
Swordfish
...3.8..2....4.7....197..8.9.5..3..6.37...52.8..5..9.3.7..961....6.3....4..8.7...
Swordfish: 1 r149 c258 => r2c8,r56c5,r68c2<>1
...........82.69..1.98.42.6..46.25..7.......8..13.74..6.34.57.9..59.38...........
(X-Wing: 7 c34 r19 => r1c259,r9c25<>7)
Swordfish: 1 r247 c589 => r1c59,r589c8,r8c59,r9c59<>1 (breaking technique)
8...6.........76...259...1...86.4...4.......6...1.83...1...679...24.........9...4
Swordfish: 1 r159 c367 => r2c3,r48c7,r8c6<>1
..31.54......7....6.49.37.55.1...3.2.7..3..5.8.2...9.71.73.62.4....1......62.75..
Swordfish: 8 c347 r258 => r2c2689,r58c9,r8c26<>8
.....4..7....9..8.6.87..3.5..4..2.1.35.....42.6.5..9..4.3..78.1.7..1....2..4.....
Swordfish: 6 r147 c458 => r28c4,r89c8,r9c5<>6
Jellyfish
..18...2.....935......6...3.65..83.1..3...4..7.23..85.1...5......718.....8...91..
Jellyfish: 4 r2349 c1348 => r18c1,r7c348,r8c8<>4
FINNED FISHES
Finned X-Wing
.....9..1...3..6.....521.89..5..4..66.9...1.27..6..8..51.983.....7..2...3..1.....
Finned X-Wing: 3 c38 r16 fr4c8 => r6c9<>3
6.21......1......3..75...8......2..9..46.87..8..4......8...95..3......2......41.8
Finned X-Wing: 5 c36 r68 fr9c3 => r8c2<>5
.6...83....37.....14.2.....6......812..981..787......5.....2.54.....97....78...1.
Finned X-Wing: 5 c16 r29 fr8c1 => r9c2<>5
Sashimi X-Wing
......847.7384..9..5...7..........76..16543..86..........4...3..8..1396.234......
Sashimi X-Wing: 2 c58 r34 fr5c8 fr6c8 => r4c7<>2 Apply additional Discontinuous Nice Loop starting on R4C6) to solve the puzzle
Finned swordfish
...7.....4....1.6.237.....4..182...5...379...3...154..6.....328.5.1....9.....6...
Finned Swordfish: 2 c247 r259 fr6c2 => r5c3<>2
..89.45636....1..8..7....1....3...5.....8.....4...6....8....1..1..8....29351.74..
Finned Swordfish: 4 r347 c159 fr7c4 => r8c5<>4
....2..3......1...7216.....18...94...56.1.38...38...15.....6597...1......3..8....
Finned Swordfish: 7 c257 r268 fr1c7 => r2c8<>7
Sashimi swordfish
...1.......9..46.8..4..857..876.....1.......9.....214..358..7..6.13..4.......1...
Sashimi Swordfish: 2 r128 c259 fr1c7 fr1c8 fr2c8 => r3c9<>2 Apply additional XY-Wing to solve the puzzle
...........51289.4.2...7.537.6..5....1.....7....6..3.246.5...8.2.37645...........
Sashimi Swordfish: 1 r367 c367 fr6c8 => r4c7<>1
3....4.7...928....1.4..7..59.1.......3..4..6.......1.28..5..6.3....615...4.8....9
Sashimi Swordfish: 2 c128 r358 fr4c2 => r5c3<>2 Apply additional Turbot Fish to solve the puzzle
8..34..65..........37.58..252.8.........9.........3.963..52.84..........18..36..9
Sashimi Swordfish: 4 r359 c347 fr3c1 => r2c3<>4
SINGLE DIGIT PATTERNS
Skyscraper
..1..7....2.14......9....719..2....5.476.931.8....4..957....1......21.3....9..5..
Skyscraper: 8 in r2c8,r8c7 (connected by r28c3) => r3c7,r9c8<>8
.1.5.43..59........4.78...........85.85.6.79.72...........21.3........17..19.5.6.
Skyscraper: 8 in r1c9,r9c7 (connected by r19c1) => r2c7,r7c9<>8
29.8564.7..6.3....7.....8...5...8.....85632.....9...8...9.....1....7.6..1.7624.98
Skyscraper: 1 in r1c3,r5c2 (connected by r15c8) => r23c2,r46c3<>1
.19......8..145....74.3.....413.9..5..2...8..9..2.734.....6.51....794..2......98.
Skyscraper: 6 in r3c9,r4c8 (connected by r34c1) => r2c8,r6c9<>6
......4...2.61.......2.567148.7.15....7...2....69.2.476195.8.......69.8...3......
Skyscraper: 4 in r2c6,r3c2 (connected by r9c26) => r2c3,r3c5<>4
..........1...6.4.5.624.71...9....25..28.14..48....6...43.951.2.5.4...3..........
Skyscraper: 7 in r1c6,r2c3 (connected by r9c36) => r1c12,r2c5<>7
.98..54....4.......2...4.19..59.7..2.6.....9.4..2.81..35.8...2.......6....61..98.
* Skyscraper: 5 in r5c4,r6c8 (connected by r8c48) => r5c9,r6c5<>5
.8.4..........6.8.216..5...4....182...25384...512....3...8..342.4.6..........7.9.
* Skyscraper: 9 in r3c4,r6c5 (connected by r36c7) => r12c5,r4c4<>9
...79.3.8.......5...8.6.7...6.4....71.75264.98....9.6...2.8.6...4.......6.5.17...
Skyscraper: 1 in r2c3,r3c9 (connected by r8c39) => r2c7,r3c2<>1
Skyscraper: 2 in r2c7,r3c4 (connected by r9c47) => r2c6,r3c9<>2
.............69..37..28.95..867....45...9...24....538..19.46..78..17.............
Skyscraper: 2 in r4c6,r6c2 (connected by r8c26) => r4c1,r6c5<>2
2-String Kite
.35...29.....6..7....38...55...7.8....8.2.5....2.4...99...36....1..9.....24...93.
2-String Kite: 4 in r2c1,r5c8 (connected by r2c7,r3c8) => r5c1<>4
..5...9......31..2236..7.8...3179...............6287...8.3..2464..86......2...1..
2-String Kite: 4 in r1c9,r6c3 (connected by r1c2,r2c3) => r6c9<>4
8......5424.76...3.....46..9...16....12...43....43...6..16.....4...97.6132......5
2-String Kite: 2 in r6c6,r8c7 (connected by r7c6,r8c4) => r6c7<>2
..2.8..93......48....1..5....3.1...6...5.7...4...9.1....7..3....18......64..7.9..
2-String Kite: 2 in r4c7,r9c4 (connected by r8c7,r9c9) => r4c4<>2
..1.435..54..7......78.....6......2....916....7......1.....19......3..87..458.3..
2-String Kite: 9 in r2c8,r4c3 (connected by r4c9,r6c8) => r2c3<>9
Turbot Fish
.....24.8.5.4192.........9.6.82..5..1.......3..3..71.4.1.........9654.1.7.51.....
Turbot Fish: 6 r2c9 =6= r9c9 -6- r9c2 =6= r7c3 => r2c3<>6
1.5.2.....7...32...395..6...8.6.......69.17.......2.8...7..536...43...1.....7.5.9
Turbot Fish: 4 r3c5 =4= r7c5 -4- r7c9 =4= r9c8 => r3c8<>4
...2.........946.2..36...84251.....86...8...57.....21937...68..8.651.........7...
Turbot Fish: 3 r1c9 =3= r8c9 -3- r8c6 =3= r9c5 => r1c5<>3
Empty Rectangle
5..9...23..284..9..7...........8..6...42391...1..5...........5..2..614..95...8..6
Empty Rectangle: 8 in b9 (r57c2) => r5c8<>8
9.1..2.......79.28......6....473..8..6.....7..9..412....7......82.36.......5..7.3
Empty Rectangle: 5 in b7 (r6c38) => r7c8<>5
1....3...965...8....7.9...17....296..9..7..4..569....36...2.3....4...526...1....7
Empty Rectangle: 5 in b7 (r6c38) => r7c8<>5
48..71..3.1..5..8...3..915.......6.8.4.....1.1.8.......241..8...5..4..2.9..82..35
Empty Rectangle: 7 in b4 (r58c4) => r8c3<>7
UNIQUENESS
Uniqueness Test 1
..6.4..23.7.56.9.....9..5.71......4...2...6...4......85.9..8.....3.29.8.82..7.1..
Uniqueness Test 1: 1/7 in r1c46,r6c46 => r6c4<>1, r6c4<>7 Apply additional XY-Chain to solve the puzzle
....7.......8...9...654183...79...28..54.27..21...73...731954...5...4.......6....
Uniqueness Test 1: 6/8 in r7c18,r8c18 => r8c8<>6, r8c8<>8 Apply additional XY-Chain to solve the puzzle
Uniqueness Test 2
.....8.31..3....4..17.3.5......2.47....865....52.1......8.4.75..7....6..39.5.....
Uniqueness Test 2: 6/8 in r3c89,r6c89 => r2c7,r3c46<>9
4...9..5..8.7....6..74..3......1.6..1..2.8..7..4.7......8..95..2....7.4..5..2...9
Uniqueness Test 2: 6/7 in r7c18,r9c18 => r24c1,r9c3<>3
....12.6......584.1.64...5........98.57...41.96........7...13.4.413......3.58....
Uniqueness Test 2: 6/9 in r2c45,r7c45 => r7c8,r8c5<>2
Uniqueness Test 3
..85.6.17.1....58.4........8...57..9..3.4.8..1..89...4........8.81....3.67.3.82..
Uniqueness Test 3: 4/9 in r2c46,r8c46 => r8c7<>7
....754.8..768.....83....5........19...369...93........6....27.....465..2.453....
Uniqueness Test 3: 4/5 in r2c12,r4c12 => r4c6<>8
7.5.32...........113..8........715.257.329.862.985........1..298...........46.8.3
Uniqueness Test 3: 3/4 in r4c13,r7c13 => r3c3<>2
Uniqueness Test 4
4.....63...7.....1.92.35..72...9.......7.3.......1...33..56.98.7.....5...85.....6
Uniqueness Test 4: 2/4 in r7c29,r8c29 => r78c2<>4
.....4..23.2.5......517.4.86..8.57.............74.9..57.9.412......2.1.91..9.....
Uniqueness Test 4: 3/6 in r8c36,r9c36 => r89c3<>3 Apply additional XY-Wing to solve the puzzle
............8..1744769.....1684.......5...8.......5716.....4952519..3............
Uniqueness Test 4: 3/9 in r2c12,r6c12 => r26c2<>3 Apply additional Skyscraper to solve the puzzle
Uniqueness Test 6
....92......7...6.7.9...2.165...8.23....7....38.2...954.1...5.6.9...7......68....
Uniqueness Test 6: 4/9 in r2c79,r9c79 => r2c7,r9c9<>9 Apply additional Skyscraper to solve the puzzle
...642.7.26............8.1653....68.....3.....91....2535.4............97.7.189...
Uniqueness Test 6: 1/8 in r1c12,r8c12 => r1c1,r8c2<>1 Apply additional Uniqueness test 1 to solve the puzzle
63.....7184.61.......8.3.........1.7.16.8.93.7.4.........2.7.......61.8919.....62
Uniqueness Test 6: 3/5 in r8c34,r9c34 => r8c3,r9c4<>3 Apply additional Uniqueness test 1 to solve the puzzle
Hidden Rectangle
965...13..789...........8....2.73.1...9.2.6...1.59.7....3...........537..27...594
Hidden Rectangle: 4/8 in r5c68,r6c68 => r5c8<>8 Apply additional 2-String Kite to solve the puzzle
.........6....81...9163..2......9.738.9...2.425.7......8..9136...75....1.........
Hidden Rectangle: 3/4 in r1c28,r2c28 => r2c8<>4 Apply additional Skyscraper to solve the puzzle
...1.5..4..3.967...9.....6..142....5.........2....147..6.....4...967.8..1..4.9...
Hidden Rectangle: 4/5 in r2c12,r8c12 => r8c2<>5 Apply additional Skyscraper to solve the puzzle
Avoidable Rectangle
..6........29....3....4.85.....94..195.6.2.844..75.....27.8....8....91........4..
Uniqueness Test 1: 3/9 in r6c78,r7c78 => r6c7<>3, r6c7<>9
Avoidable Rectangle Type 1: 2/9 in r1c79,r6c79 => r1c9<>2
6........3.....41212.5......3.98.7.1..16.32..4.8.71.3......6.93813.....6........7
Uniqueness Test 1: 1/8 in r7c47,r9c47 => r9c4<>1, r9c4<>8
Avoidable Rectangle Type 1: 3/1 in r1c45,r9c45 => r1c5<>3
BUG + 1
15.6..49..7.4.......397...8.158...................356.2...841.......1.8..91..7.45
Bivalue Universal Grave + 1 => r5c1<>3, r5c1<>6
..94....6..4...13......8.9.95...7.....2.4.3.....8...21.2.9......63...5..1....64..
Bivalue Universal Grave + 1 => r1c7<>2, r1c7<>8
.715236...........5.61.........8..69.64.5.32.78..3.........64.3...........784295.
Bivalue Universal Grave + 1 => r7c2<>2, r7c2<>5
Uniqueness All
.61......7....3.9.5...6...2....5428...........1432....6...8...7.2.4....5......34.
Hidden Rectangle: 5/7 in r5c23,r9c23 => r5c2<>7 Apply additional X-Chain to solve the puzzle
......3..132.74....45.....8.1.6..9.............4..1.3.8.....62....52.489..7......
Uniqueness Test 3: 2/5 in r4c16,r5c16 => r4c5<>8 Apply additional XY-Chain to solve the puzzle
..723....96....5.8.41...6..........6...182...8..........3...45.1.4....69....742..
Uniqueness Test 4: 3/5 in r4c46,r8c46 => r4c46<>5 Apply additional W-Wing and XY-Chain to solve the puzzle
.....9....5..6482.4.1.2.6....8..2..7...6.3...7..1..2....7.4.1.3.6483..5....9.....
Hidden Rectangle: 2/8 in r1c12,r9c12 => r9c1<>2 Apply additional XY-Chain to solve the puzzle
3....6.9...4....5.....7.6.2...39.1848...4...6492.68...7.5.3.....8....5...1.8....7
Hidden Rectangle: 1/8 in r1c59,r2c59 => r2c5<>1 Apply additional XY-Chain to solve the puzzle
..5.1...6169.3..4..4............841....349....261............5..3..9.1872...7.3..
Uniqueness Test 6: 2/5 in r2c46,r8c46 => r2c4,r8c6<>2 Apply additional Hidden Rectangle and XY-Chain to solve the puzzle
12...863753.71...............5.....1...573...4.....2...............91.622793...84
Uniqueness Test 4: 2/6 in r3c46,r4c46 => r34c6<>6 Apply additional XY-Chain to solve the puzzle
...15..........247..37.68...3...15..2..635..4..52...6...84.29..159..........93...
Uniqueness Test 3: 4/9 in r3c12,r6c12 => r4c13<>7 Apply additional Hidden Rectangle and XY-Chain to solve the puzzle
54.......39.5.24..........9.5.8...31...735...62...1.8.1..........69.8.14.......23
Uniqueness Test 1: 1/3 in r1c47,r3c47 => r1c4<>1, r1c4<>3 Apply additional XY-Chain to solve the puzzle
1..328..58......3..65........68.245...........276.41........31..1......46..137..2
Uniqueness Test 6: 1/9 in r2c69,r3c69 => r2c6,r3c9<>1 Apply additional XY-Chain to solve the puzzle
....3.....2.8..3.1..35...24351...7.9.........2.7...45817...38..4.9..1.3.....2....
Uniqueness Test 2: 6/9 in r7c48,r9c48 => r7c5,r8c45,r9c6<>6
WINGS
XY-Wing
12........4.82.3.......76..7..1...8.5.......2.1...4..6..87.......5.93.7........94
XY-Wing: 1/9/5 in r2c8,r34c9 => r12c9,r6c8<>5
.5..83714.....43..........6.1.2....8.968.724.2....9.7.4..........54.....93156..2.
XY-Wing: 1/8/7 in r2c15,r8c1 => r8c5<>7
.765......2.......9..7...616..82.3....4.5.8....2.36..516...4..8.......7......961.
XY-Wing: 3/8/4 in r1c18,r2c9 => r1c79,r2c1<>4
XYZ-Wing
...1.......2.83.1.1....54.39......4..238.976..7......28.13....6.5.72.1.......6...
XYZ-Wing: 3/5/8 in r4c79,r9c7 => r6c7<>8
.....5.....9.62.1.2.54.7..8.23......1..7.9..2......68.7..2.84.3.4.37.8.....9.....
XYZ-Wing: 5/6/9 in r57c2,r8c1 => r9c2<>5
4.....53.7....19...9...524...9362...............9178...635...1...71....9.54.....8
XYZ-Wing: 2/3/6 in r5c19,r6c3 => r5c3<>2
W-Wing
8.....3.4.74.....9....34.1..5.623...............491.7..9.56....1.....46.6.3.....5
W-Wing: 8/7 in r5c4,r8c5 connected by 7 in r1c45 => r5c5<>8
67.13......16......8...56.2.......51.59...32.71.......9.72...3......92......18.96
W-Wing: 2/4 in r1c6,r6c3 connected by 4 in r16c9 => r1c3<>2
.6.93..5..5.7...8...4...7....93....88.......55....26....2...8...1...3.2..7..21.6.
W-Wing: 9/1 in r2c7,r3c1 connected by 1 in r23c5 => r2c1,r3c89<>9
CHAINS
Remote Pair
8.43.........2.18..7651.........5.64.9.....2.16.2.........5627..27.3.........24.5
Remote Pair: 7/6 r1c7 -6- r2c9 -7- r2c4 -6- r5c4 => r5c7<>7
1469.5...2......8.....1.6.....35..97.........91..47.....2.9.....6......4...2.4875
Remote Pair: 7/5 r3c1 -5- r2c2 -7- r7c2 -5- r7c4 => r3c4<>7
.7..6.59..1............2136..2.16....8.....5....39.2..8956............7..67.5..4.
Remote Pair: 3/1 r1c6 -1- r9c6 -3- r9c1 -1- r8c3 => r1c3<>3
X-Chain
....6....7.23.9..686.2....1145..........9..........7132....6.476..8.21.9....1....
X-Chain: 4 r1c1 =4= r9c1 -4- r8c3 =4= r8c5 -4- r2c5 =4= r2c7 => r1c79<>4
XY-Chain
68..5......73.....91.6..42.24..........793..........89.52..1.36.....58......6..54
XY-Chain: 4 4- r2c5 -1- r4c5 -8- r4c6 -6- r6c6 -4 => r2c6<>4
...619...8.....92.....3.4...2.....96.6.3.7.4.45.....3...5.2.....34.....7...753...
XY-Chain: 2 2- r1c1 -3- r4c1 -7- r6c3 -9- r3c3 -7- r3c2 -9- r9c2 -8- r9c8 -1- r9c3 -2 => r1c3,r89c1<>2
.....2.3...6..914.8.1.7...535..........4.5..........132...1.6.4.475..8...1.8.....
XY-Chain: 8 8- r4c8 -6- r4c5 -9- r4c9 -7- r5c9 -9- r5c3 -8 => r4c3,r5c8<>8
AIC
9.41......7.6....4285........281.9.............6.458........4733....7.1......12.8
AIC: 5 5- r5c9 -6- r4c8 =6= r4c6 =3= r1c6 =8= r1c8 -8- r2c8 -9- r9c8 -5 => r45c8,r8c9<>5
Frank's solution:
R9C8-9-R2C8-8-R1C8-3-R1C6=3=R4C6=6=R4C8-6-R5C9 => R8C9 <> 5
356....2.......7....749..3...4..8..9...6.2...1..9..3...1..478....5.......7....496
AIC: 5 5- r2c9 -8- r2c8 =8= r6c8 -8- r6c3 -2- r6c9 =2= r4c7 =6= r3c7 -6- r3c6 -5 => r2c456,r3c79<>5
Frank's solution:
R3C6-6-R3C7=6=R4C7=2=R4C2=3=R5C3=8=R5C9-8-R2C9 => R2C456, R3C79 <> 5
.....6..23.42....1.....843......4179.........6571......328.....7....15.38..6.....
AIC: 4 4- r1c5 -3- r1c4 =3= r5c4 =7= r3c4 -7- r3c9 =7= r1c7 -7- r1c2 =7= r2c2 =6= r8c2 =4= r8c4 -4 => r1c4,r79c5<>4
...1.56.4....8......2..91.7.35.....84..258..66.....75.3.64..8......3....2.98.6...
AIC: 4 4- r3c2 =4= r3c5 =6= r3c4 -6- r4c4 -9- r4c1 -1- r2c1 =1= r2c3 =4= r8c3 -4 => r2c3,r89c2<>4
Frank's solution:
R3C2=4=R2C3=1=R2C1=9=R4C1-9-R4C4-6-R3C4-3-R2C6 =>R3C5 <> 4
.1......9....7.143...3...5....5.43...3298156...47.6....5...3...847.9....3......8.
AIC: 9 9- r4c8 -7- r1c8 =7= r1c7 =8= r1c6 -8- r2c6 =8= r2c2 -8- r6c2 -9 => r4c123,r6c78<>9
25...41........3.......1.427.....68..18.9.42..34.....747.5.......3........28...34
AIC: 1/8 1- r2c1 -8- r3c2 =8= r3c7 -8- r7c7 =8= r7c9 =1= r7c3 -1- r8c1 -8 => r8c1<>1, r2c1<>8
Frank's solution:
R7C7=8=R7C9=1=R7C3-1-R2C3=1=R2C1=8=R3C2 =>R3C7 <> 8
.8..1....231.....99...26.....5..72..49..5..18..28..5.....94...61.....972....7..5.
AIC: 3 3- r5c6 -2- r5c4 =2= r9c4 -2- r9c2 -6- r4c2 -1- r4c4 -4- r6c6 =4= r2c6 =5= r2c4 -5- r8c4 -6- r8c5 -3 => r46c5,r789c6<>3
ALMOST LOCKED SETS
ALS XZ-Rule
8...4..51.3..514.8154..86......841.7.41...89.6.81...4.4.751.28.2834...1..1.82...4
Almost Locked Set XZ-Rule: A=r5c145 {2367}, B=r123c4,r3c5 {23679}, X=2, Z=6 => r4c4<>6
ALS XZ-Rule double linked
..1.....7...89..........6..26..3.......5...749...........1.4.5.83.............2..
Almost Locked Set XZ-Rule: A=r3c3789 {13469}, B=r124c7 {1239}, X=1,3 => r12c8<>1, r3c2<>9
4..53..7..1...........6.4.21....28..83.175.2...968...17.8.5....3.1....8..9..18..3
Almost Locked Set XZ-Rule: A=r1c2379 {12689}, B=r23469c8 {134569}, X=1,9 => r2c9<>9, r7c8<>4, r7c8<>6
ALS XY-Wing
6...7..85......6...853..1...18.....6..9.2.7..4.....93...7..436...4......23..5...9
Hidden Rectangle: 7/9 in r2c18,r3c18 => r2c8<>7
Discontinuous Nice Loop: 4 r4c8 -4- r9c8 =4= r9c7 -4- r1c7 -2- r4c7 =2= r4c8 => r4c8<>4
Hidden Rectangle: 2/5 in r4c78,r8c78 => r8c7<>2
Almost Locked Set XY-Wing: A=r6c59 {168}, B=r3678c9 {12478}, C=r3c5 {46}, X,Y=4,6, Z=8 => r6c46<>8
Brute Force (= Solve)
Death blossom
8...34.6.4.61......7928.....82......9..751..8......59.....9213......79.2.9.41...6
XY-Wing: 2/7/8 in r19c7,r2c8 => r2c7,r89c8<>8
Hidden Rectangle: 5/8 in r7c34,r8c34 => r8c3<>5
Death Blossom: [r9c3], -3- r8c1 {13}, -5- r1c3 {15}, -7- r389c8 {1457} => r3c1<>1
Skyscraper: 5 in r2c6,r8c4 (connected by r28c2) => r1c4,r9c6<>5
...7915........9.45.1......1....64...3..8..2...92....6......6.72.5........6943...
Hidden Rectangle: 4/8 in r7c28,r8c28 => r8c2<>8
Death Blossom: [r6c1], -4- r5c379 {1457}, -7- r9c18 {578}, -8- r4c2345 {23578} => r4c8<>5
Brute Force (= Solve)
3..9..4..8...1......6..8..959.4.......2...3.......9.749..8..1......7...5..8..2..7
Swordfish: 7 r147 c236 => r2c26,r35c2,r5c6<>7
Death Blossom: [r5c4], -1- r7c56,r89c4 {13456}, -5- r9c4 {35}, -6- r4c5 {36}, -7- r4c5689 {12367} => r6c4<>3
Brute Force (= Solve)
1..5...6.....8.1.2.....14.......8..97.46.58.16..7.......98.....4.2.3.....3...4..6
2-String Kite: 2 in r3c1,r5c5 (connected by r4c1,r5c2) => r3c5<>2
Death Blossom: [r1c5], -2- r456c5,r6c6 {12349}, -4- r2389c4 {12349}, -7- r1c379 {3789}, -9- r1c379 {3789} => r1c6<>3
Brute Force (= Solve)
LOOPS
Continuous nice loop
.27...8.....5....44859...1....4...9...32.54...6...8....9...26477....9.....1...93.
Continuous Nice Loop: 6/7/8 8= r5c8 =6= r2c8 -6- r2c1 =6= r1c1 -6- r1c4 =6= r9c4 =8= r9c9 -8- r8c8 =8= r5c8 =6 => r1c56,r2c6<>6, r5c8,r9c4<>7, r8c9<>8
Frank's solution:
R6C4=7=R9C4=8=R9C9-8-R8C8-2-R6C8-7-R6C4
.38.......157.4.3...6..5..7.435....2.........8....137.3..1..7...5.8.926.......84.
Continuous Nice Loop: 1/2/3/6/9 6= r5c4 =2= r5c5 =3= r3c5 =8= r3c8 =2= r1c8 -2- r1c6 -6- r1c4 =6= r5c4 =2 => r3c58<>1, r13c5<>2, r5c4<>3, r15c5<>6, r3c58,r5c45<>9
.4....3..86.5..41...7....569...41......9.5......67...842....6...56..4.83..3....4.
Continuous Nice Loop: 1/2/9 5= r1c3 =1= r5c3 -1- r5c7 =1= r6c7 =5= r6c1 -5- r1c1 =5= r1c3 =1 => r5c2<>1, r1c3,r6c7<>2, r1c3,r6c7<>9
Frank's solution (0:12:00) :
R6C1=5=R6C7=1=R5C7-1-R6C3=1=R1C3=5=R1C1-5-R6C1
Discontinuous nice loop
.9.51.3...7.6..1.....3....7..725....61.....78....769..7....3.....9..2.6...2.45.1.
Discontinuous Nice Loop: 4/6/8 r3c3 =1= r3c1 -1- r8c1 =1= r8c4 =7= r8c7 -7- r9c7 -8- r9c1 =8= r7c3 =1= r3c3 => r3c3<>4, r3c3<>6, r3c3<>8
Frank's solution (0:30:00):
R7C3-8-R9C1=8=R9C7=7=R8C7-7-R8C4-1-R7C4=1=R7C3 => R7C3 <> 8
9....1....6...381...1.2..9...374.......169.......851...2..3.6...962...8....5....7
Discontinuous Nice Loop: 5/6/8 r4c9 =9= r4c7 -9- r9c7 =9= r9c5 =1= r8c5 -1- r8c9 =1= r7c9 =9= r4c9 => r4c9<>5, r4c9<>6, r4c9<>8
Frank's solution:
R7C4=9=R9C5=1=R8C5-1-R8C9=1=R7C9=9=R7C4 => R7C4 = 9
.1..59..353......8..96......5..14.....8...4.....28..7......28..7......351..36..2.
Discontinuous Nice Loop: 1/4/7/9 r7c4 =5= r7c3 =3= r4c3 -3- r4c7 =3= r6c7 =5= r6c6 -5- r9c6 =5= r7c4 => r7c4<>1, r7c4<>4, r7c4<>7, r7c4<>9
.1..4..8.7692.....8..5.9...45.........1.8.4.........13...6.3..8.....7965.2..5..3.
Discontinuous Nice Loop: 2/6/7/8 r6c7 =5= r6c6 =4= r9c6 -4- r9c9 =4= r2c9 -4- r2c8 -5- r2c7 =5= r6c7 => r6c7<>2, r6c7<>6, r6c7<>7, r6c7<>8
Frank's solution:
R4C6=1=R4C4-1-R8C4-4-R9C6=4=R9C9-4-R2C9=4=R2C8=5=R5C8-5-R5C6-2-R4C6 =>R4C6 <> 2
8.2..........64...4152.....3.9....2....895....5....7.9.....8271...61..........4.5
Discontinuous Nice Loop: 1/7 r4c6 =6= r4c9 =8= r4c2 -8- r9c2 =8= r9c3 =1= r9c1 -1- r6c1 -6- r6c6 =6= r4c6 => r4c6<>1, r4c6<>7
Frank's solution:
R4C6=6=R6C6-6-R6C1-1-R9C1=1=R9C3=8=R6C3-8-R6C8=8=R4C9=6=R4C6 =>R4C6 = 6
1.........4..12875.829.......7......6.38.51.7......6.......679.72459..8.........4
Discontinuous Nice Loop: 3/6/7 r3c5 =5= r3c1 -5- r7c1 =5= r7c3 =1= r7c9 -1- r3c9 =1= r3c8 =6= r1c8 -6- r1c3 -5- r1c5 =5= r3c5 => r3c5<>3, r3c5<>6, r3c5<>7
5...864.92....3.1.4.........653.....1...2...5.....589.........4.2.7....33.456...8
Discontinuous Nice Loop: 9 r2c3 -9- r5c3 =9= r4c1 -9- r7c1 -6- r7c8 =6= r5c8 =3= r5c7 -3- r3c7 =3= r3c3 =6= r2c3 => r2c3<>9
1.........7..5.6.......9271.641.....2.......5.....894.7925.......8.3..6.........2
Discontinuous Nice Loop: 1/3/5 r6c3 =7= r6c4 -7- r4c5 -9- r4c1 =9= r5c3 =7= r6c3 => r6c3<>1, r6c3<>3, r6c3<>5
Grouped continuous nice loop
Grouped continuous nice loop with ALS
..1.....7...89..........6..26..3.......5..9749.....3.....1.4.5383.............2..
Grouped Continuous Nice Loop: 4/5/6/7/8 6= r7c5 =2= r7c23 -2- ALS:r4689c3 -6- r7c13 =6= r7c5 =2 => r23c3<>4, r23c3<>5, r9c1<>6, r237c3,r7c5<>7, r7c5<>8
MISCELLANEOUS
Sue de Coq
215.8679.64..725..37..512...845.9....637.89...921.38..927834..5456217389831695427
Sue de Coq: r23c8 - {1346} (r7c8 - {16}, r1c9 - {34}) => r2c9<>3, r3c9<>4, r5c8<>1
Sue de Coq: r12c9 - {1348} (r36c9 - {468}, r2c8 - {13}) => r4c9<>6, r5c9<>4
519.386.7.276....96.49.....162745983..5.6.7....3829516..6...37...1..629.2.859..6.
Sue de Coq: r78c4 - {1234} (r1c4 - {24}, r78c5,r9c6 - {1378}) => r7c6<>1
4..2..1..2.7....4.....473.28236719541458....37694532183.2964.........4....4..8...
Sue de Coq: r3c123 - {15689} (r3c4 - {15}, r1c3 - {68}) => r12c2<>8, r12c2,r3c8<>9
..72163452.6.4.79.5.4..7.6.....8.6.7...672...769.5..8.6..1..473.4.7..8.6.73.64.2.
Sue de Coq: r23c4 - {3589} (r9c4 - {58}, r3c5 - {39}) => r2c6<>3
.....53..4.9.2.5...529..478..7289145215.7.98.948.512.7524..78......92654.9.5..7..
Sue de Coq: r89c1 - {1678} (r34c1 - {136}, r8c2 - {78}) => r1c1<>1
.42.53.......1.26.3..6......1...27...7.....5...91...2......9..7.68.3.......76.53.
Sue de Coq: r5c456 - {34689} (r5c3 - {36}, r4c5 - {489}) => r4c4,r6c6<>4, r4c4,r6c6<>8, r5c7<>3, r5c9<>6
COMBINED TECHNIQUES
Refer to LEGENDA for the meaning of the numbers below each Sudoku string
Note that the order of the solution techniques is arbitrary
2 stars is relative easy, 5 stars is very difficult (and time consuming!)
**
18.4.............6.72.96.5...38...49.4.2.3.7.71...93...2.58.96.8.............1.87
1 (2x), 43
95.7.....1..54.9...2....5....7.84....4.....5....16.7....3....6...5.31..2.....2.45
1, 11, 41
5.1....7...29.......9..83.212...3.8...........6.8...342.54..8.......29...4....5.3
11 (2x), 51
576.......3196.2.....1.7..........62.57.3.89.64..........7.6.....3.4957.......946
1, 11, 43
....89.....83.1.79.3.4..8...245.......9...6.......841...2..3.4.36.1.29.....89....
11, 12, 14
...8.219....4..2.7....9..8628...9.....3...7.....3...6164..8....8.5..7....926.1...
11, 12, 14
.......282.5.4..6..3..52........64...6193875...35........21..3..1..8.2.687.......
12 (2x), 41, 43
...8..1.......524.9561....734.6.........1.........3.621....4378.823.......3..6...
1, 11, 12
.....821....7..3.8..3.2..7.2..6..9....1...7....9..4..3.3..4.6..9.8..1....523.....
12, 14, 43
........6.8..9..2.2.75...9...5.193..9.1...8.2..637.9...9...52.3.6..8..5.5........
12, 14
..845..6.7...26.....4.1...25......2...63729...1......74...9.2.....53...6.3..814..
11, 12, 14, 27, 43
.47...1..2.81.493...............76.2.32.9.47.7.52...............749.65.3..3...24.
11, 12, 14, 51 (2x)
***
85.294.6.2.1.8..5..963152.8.2.8..5..1..5....4..5..9.2.51.4.368.......3.5.6.958..2
11, 12, 41 (2x), 42, 43 (2x)
..34.59...452....6.8..3...435.8.........6.........1.574...9..8.8....471...17.86..
11, 12, 26
.47.1.6..6.89.............82..46..1...1.9.8...7..21..51.............25.7..3.5.28.
11, 12
.....82..2..9.....9..32.4.1.12.3.6..3..2.5..8..5.4.72.5.1.83..2.....2..4..87.....
11, 12, 41
5...6.....23.9.18..98..7........34.5.4.....2.9.26........5..96..79.4.51.....1...2
11, 12, 13 (2x)
.915..6.....6....5.....3.8..5.....9.3..4.2..1.6.....2..8.9.....5....1.....7..683.
11, 12, 14, 43
7..3.469...395...4..98.23.7.3.2.....9.......3.....3.6.3.41.59..2...398...974....5
11, 12 (2x), 14 (2x)
....8....9.27...4..6......2.2957.6....7.6.3....8.4972.5......6..1...85.9....5....
1, 11, 12, 14
..956.72......4...76........2394..1..9.....6..7..1529........42...3......85.276..
11, 12 (3x), 14
6..5.4....2......145...19.6..49.36...6.....1...21.64..9.64...353......9....8.9..4
11, 12, 13, 14
..57....2.69.5.8........1....4.61...1.7...2.6...82.4....3........8.1.59.4....86..
11, 12, 14
....43.9....6.2..56.8......2.9....6....8.6....7....4.8......1.24..2.9....3.76....
12, 13, 14, 42
.......7.397..........76.31..27...6381..3..4767...51..53.41..........854.6.......
11, 12, 13 (2x), 14, 29
8....9....95.....3..3.2.9.8139..6..2....3....6..8..3415.7.8.4..3.....21....6....5
2 (2x), 11, 12 (3x), 23, 27 (2x), 43 (4x)
4.3..79.17...4.....2.91......8....6...25381...5....8......81.7.....6...25.43..6.8
1 (2x), 12 (2x), 41 (2x), 43 (2x)
9.....2...6.8...4983....6......67....7.529.8....48......9....5758...3.2...3.....1
12 (2x), 23, 41, 42 (2x), 43 (2x)
.9....325..86..........2.8.95..2.....12.8.56.....5..42.8.1..........46..671....9.
1, 21, 22, 41, 42, 43 (2x)
****
5..2.........37...76..45.32..6....2..953.164..4....1..21.47..68...81.........2..4
1, 12, 27, 41 (2x), 43, 53
*****
.8...531.1.53...7......7.8....69.....49...63.....43....9.4......5...91.7.175...2.
21, 43, 53 (2x), 91
.6.....2......7..42.....65.7.614.2.............4.539.7.83.....61..8......5.....3.
1, 11, 27, 41, 71
....1..2....24.1.8.7.5.......9....423...7...121....5.......6.8.9.4.38....3..2....
4, 43, 53, 54
.....8..7....7...1...5.983.3...4..68.65...74.47..8...2.849.1...9...5....7..4.....
11, 12, 13, 27, 43 (2x), 54
15.98..6.9.7.......684.....6......295...6...482....6.5..6..5.1...5...3.7.8..93.56
4, 5, 11, 12 (2x), 41 (2x), 42, 43, 53, 71, 91
8...5......96..8..361....9.5..837.......1.......965..3.7....345..4..36......7...1
1, 4, 6, 21, 53 (2x), 54, 71, 91
7..359.16.....72..19.....7.......96....761....31.......7.....54..92.....85.174..2
27 (2x), 72
67......8....2.....52.761..4...8..9...82914...1..5...6..394.61.....6....5......72
1, 12, 43, 53, 54
7.1..........725.9.6.8.....4.....27....4.5....36.....1.....1.8.6.752..........4.7
43, 71
9..3...752.691.........7.....1.....2.9.....3.3.....6.....8.........615.774...3..1
11, 27, 43, 71
.6.4.278..8..764.....1....68..........5.3.1..........21....5.....924..1..729.3.5.
27, 41, 43, 71
......3.......2.1.....942763..28.64...........69.13..784536.....9.8.......7......
12, 43, 71
38......1..217.........5..2.7.5..349..53.96..963..4.2.4..9.........271..7......93
41, 54
....41.6.1...7..42...2..713.25......3...1...7......65.513..6...24..3...6.8.42....
12, 43 (2x), 71
..5.........7..58.68....1.92.49.7......3.2......8.47.11.8....56.96..8.........2..
12, 43 (3x), 72
7............2.8.....4.513.2...384.51.......38.527...9.163.2.....2.5............1
12, 43, 71
15.2..7.6.....32..........97.5.8.3....13.59....6.7.1.85..........37.....4.7..1.25
11, 41, 71
.....5.96.91...54.7..9..8...1.78...3.........4...36.1...6..7..4.89...27.27.8.....
5, 71
..6....2..9..4.65....71....4.8..71.............51..4.6....28....17.5..9..5....2..
54, 71
1.23.9.4.9..7..........21...784........936........123...45..........7..9.5.2.38.4
12, 41, 71
..7......32.1...6.9..3.4......942.17....5....29.763......4.7..3.1...9.24......7..
43, 71
..2....56...85.....3...98...6.971.84.........89.625.1...75...9.....32...65....7..
27, 53, 71
1..7.........54.1734.9.......5....417...6...323....9.......7.9858.12.........3..5
27, 71
7......81...173....9...847......92..83.....97..94......826...5....325...35......4
41 (2x), 53, 71
3......7.9..4..5311..5.6.8.48...9...............2...49.7.6.1..3639..4..7.1......5
24, 43, 71
...95.2..1...2..6...2..748.86........19...82........36.274..6...3..8...4..1.75...
11, 27, 71
...56...7.62.749.........1..48......7.......8......56..3.........128.63.8...91...
11, 71
....2....4....759..7...63..15....2.....174.....8....61..35...8..628....4....6....
41, 53, 71
..8.5..6.2......39..132.....43.15...............48.15.....489..78......4.3..6.5..
53, 71
9..8.2....7......8..17.6.....9...27.6..923..1.82...9.....4.16..7......3....5.8..2
51, 71
.7.5...2.......61......6..79....726.86.1.9.74.526....85..9......29.......1...4.5.
43, 71
63.51......1..2...97........2.8.75.1.6.....9.3.51.4.2........58...2..9......51.62
12, 71
.8.49.52..5...89.6........8..1.59...............38.7..8........5.27...8..39.26.4.
27, 71
........6..5....78..78362.....3..1...1..6..4...9..1.....67435..87....6..2........
11, 42, 71
.841...7.5.7.64...3...........24..9.25.3.7.64.7..89...........2...53.7.6.3...295.
12, 41, 71
1.3...........71...8..9.5.22..6.5...41..7..59...9.4..88.2.3..7...15...........9.5
42, 71
74.2.....52..31.......45.1.2..1..5...7.....9...4..3..2.9.48.......35..24.....2.73
27, 72 (7x), 64, 11 (2x)
....7.........82.74....1.962...958.............678...292.6....46.54.........2....
21, 72. 64, 72 (2x), 13, 5, 41
75......2...48.........54..4.5..687...9.7.6...762..5.1..81.........93...1......46
42, 72 (4x), 63, 64, 51
LEGENDA
Basic Fish **
01. X-Wing
02. Swordfish
03. Jellyfish
Finned/Sashimi Fish ***
04. Finned/Sashimi X-Wing
05. Finned/Sashimi Swordfish
06. Finned/Sashimi Jellyfish
Single Digit Patterns **
11. Skyscraper
12. 2-String Kite
13. Turbot Fish
14. Empty Rectangle
Uniqueness **
21. Unique Rectangle Type 1
22. Unique Rectangle Type 2
23. Unique Rectangle Type 3
24. Unique Rectangle Type 4
25. Unique Rectangle Type 5
26. Unique Rectangle Type 6
27. Hidden Rectangle
28. Avoidable Rectangle
29. BUG+1 - Binary Universal Grave + 1
30. Unique Rectangles with missing candidates
Wings ***
41. XY-Wing
42. XYZ-Wing
43. W-Wing
Chains
51. Remote Pair **
52. X-Chain ***
53. XY-Chain ****
54. AIC *****
ALS - Almost Locked Sets
61. ALS-XZ ****
62. ALS-XY-Wing *****
63. ALS Chain *****
64. Death Blossom *****
Loops *****
71. (Grouped) Continuous Nice Loop
72. (Grouped) Discontinuous Nice Loop
73. Grouped Continuous Nice Loop with ALS
74. Grouped Discontinuous Nice Loop with ALS
Coloring ***
81. Simple Colors (Color Wrap/Color Trap)
82. Multi Colors
Miscellaneous
91. Sue de Coq ****
Notes:
weak link x -1- y means if cell x is a 1, cell y can not contain a 1
strong link x =1= y means if cell x is not a 1, cell y must be 1
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Source code:
<![CDATA[<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="viewport" content="width=device-width, height=device-height, initial-scale=0.68, user-scalable=no"/>
<title></title>
<style type="text/css">
body
{
font-size: 1.1em;
font-family: verdana, arial, sans-serif;
background-color: #faebd7;
}
clock
{
text-align: right;
}
td
{
padding-bottom:5px;
}
button
{
width: 130px;
height:40px;
margin-top: 8px;
background-color: #bbbbbb;
border-radius: 5%;
font-size: 16px;
touch-action: manipulation; // Specific for IOS: Disable zoom in and zoom out
}
canvas
{
background-color: #ffffe0; // LightYellow
padding-bottom:10px;
display:block;
touch-action: manipulation; // Specific for IOS: Disable zoom in and zoom out
}
#sudoku
{
margin-left:auto;
margin-right:auto;
width: 570px;
height:1010px;
background-color: #fefefe;
padding:10px;
}
#banner
{
position: relative;
left: 0px;
top:0px;
padding: 5px;
}
#main
{
top:60px;
padding: 10px;
float:left;
}
#big
{
font-size: 32px;
color:#448844;
}
#small
{
display:block;
font-size: 10px;
}
</style>
<script type="text/javascript" >
// Code written by Frank Alleman in 2021.
// You are free to use this code for whatever purpose.
var BoxSize = 3;
var BoardSize = BoxSize * BoxSize;
function Undostack() {
this._position = -1;
this._undostack = Array();
}
Undostack.prototype.push = function(board, compare = true) {
while (this._undostack.length > this._position + 1)
this._undostack.pop();
if (this._undostack.length > 0 && compare && board.equals(this._undostack[this._undostack.length - 1])) {
}
else {
this._undostack.push(board.clone());
this._position = this._undostack.length - 1;
}
};
Undostack.prototype.undo = function(target) {
var retval = false;
if (this._position > 0) {
this._undostack[--this._position].copyTo(target);
retval = true;
}
return retval;
};
Undostack.prototype.redo = function(target) {
var retval = false;
if (this._position + 1 < this._undostack.length) {
this._undostack[++this._position].copyTo(target);
retval = true;
}
return retval;
};
Undostack.prototype.clear = function() {
this._position = -1;
this._undostack = Array();
};
function Candidates(n) {
this._mask = n;
}
Candidates.prototype.count = function () {
// Count number of on bits from 1..9
var count = 0;
for (var i = 1; i <= BoardSize; i++)
if ((this._mask & (1 << i)) != 0)
count++;
return count;
};
Candidates.prototype.update = function (contains) {
var count = 0;
for (var i = 1; i <= BoardSize; i++)
if ((this._mask & (1 << i)) != (contains & (1 << i)))
if ((this._mask & (1 << i)) != 0)
this._mask = (this._mask ^ (1 << i));
};
Candidates.prototype.hasCandidate = function (n) {
return n >= 1 && n <= BoardSize && ((this._mask & (1 << n)) != 0);
};
Candidates.prototype.addCandidate = function (bitmask) {
this._mask |= bitmask;
};
Candidates.prototype.removeCandidate = function (bitmask) {
this._mask &= ~bitmask;
};
Candidates.prototype.candidatesArray = function () {
var ret = new Array();
for (var i = 1; i <= BoardSize; i++)
if (((1 << i) & this._mask) != 0)
ret.push(i);
return ret;
};
Candidates.prototype.isCandidateVisible = function (digit) {
if ((this._mask & (1 << digit)) != 0)
return true;
return false;
}
Candidates.prototype.getSingle = function () {
var ret = 0;
for (var i = 1; i <= BoardSize; i++)
if (((1 << i) & this._mask) != 0) {
ret = i;
break;
}
return ret;
};
Candidates.prototype.clone = function () {
return new Candidates(this._mask);
};
Candidates.prototype.equals = function (candidate) {
if (this._mask != candidate._mask)
return false;
return true;
};
Candidates.prototype.logicalAnd = function (bitmask) {
return (this._mask &= bitmask);
};
function Cell(digit) {
this._digit = digit; // 0 means unassigned
this._candidatescorner = new Candidates(0);
this._candidatescentre = new Candidates(0);
this._candidatesvisible = new Candidates(0);
this._given = false;
this._backgroundcolor1 = "";
this._backgroundcolor2 = "";
this._backgroundcolor3 = "";
}
Cell.prototype.getSingle = function () {
return this._candidatescorner.getSingle();
};
Cell.prototype.getDigit = function () {
return this._digit;
};
Cell.prototype.setDigit = function (n) {
if (n < 0 || n > 9)
throw "Illegal value not in the range 1..9.";
this._digit = n;
this._given = false;
};
Cell.prototype.setGiven = function (n) {
if (n < 0 || n > 9)
throw "Illegal value not in the range 1..9.";
this._digit = n;
this._given = n != 0;
};
Cell.prototype.getColor = function (opt) {
switch (opt) {
case 1:
return this._backgroundcolor1;
case 2:
return this._backgroundcolor2;
case 3:
return this._backgroundcolor3;
}
};
Cell.prototype.setColor = function (color = "#ffffe0", opt = "split") {
if (opt == "noSplit") {
this._backgroundcolor1 = color;
this._backgroundcolor2 = "";
this._backgroundcolor3 = "";
return;
}
if (color == "#ffffe0") { // LightYellow, note that color == "LightYellow" doesn't work!
this._backgroundcolor1 = color;
this._backgroundcolor2 = "";
this._backgroundcolor3 = "";
return;
}
if (color == "#ffdead") { // NavajoWhite, note that color == "NavajoWhite" doesn't work!
this._backgroundcolor1 = color;
this._backgroundcolor2 = "";
this._backgroundcolor3 = "";
return;
}
if (color == "#ff0000") {
// indicates value in cell not valid
this._backgroundcolor1 = color;
this._backgroundcolor2 = "";
this._backgroundcolor3 = "";
}
else {
if (color == this._backgroundcolor1) {
this._backgroundcolor1 = this._backgroundcolor2;
this._backgroundcolor2 = this._backgroundcolor3;
this._backgroundcolor3 = "";
if (this._backgroundcolor1 === "")
this._backgroundcolor1 = "#ffffe0";
}
else if (color == this._backgroundcolor2) {
this._backgroundcolor2 = this._backgroundcolor3;
this._backgroundcolor3 = "";
}
else if (color == this._backgroundcolor3)
this._backgroundcolor3 = "";
else {
if (this._backgroundcolor1 == "#ffffe0")
this._backgroundcolor1 = color;
else if (this._backgroundcolor2 === "")
this._backgroundcolor2 = color;
else if (this._backgroundcolor3 === "")
this._backgroundcolor3 = color;
}
}
}
Cell.prototype.getCandidatesCorner = function () {
return this._candidatescorner._mask;
};
Cell.prototype.setCandidatesCorner = function (bitmask) {
this._candidatescorner._mask = bitmask;
};
Cell.prototype.getCandidatesCentre = function () {
return this._candidatescentre._mask;
};
Cell.prototype.setCandidatesCentre = function (bitmask) {
this._candidatescentre._mask = bitmask;
};
Cell.prototype.getCandidatesVisible = function () {
return this._candidatesvisible._mask;
};
Cell.prototype.setCandidatesVisible = function (bitmask) {
this._candidatesvisible._mask = bitmask;
};
Cell.prototype.removeAllCandidatesCorner = function () {
this._candidatescorner = new Candidates(0);
};
Cell.prototype.removeAllCandidatesCentre = function () {
this._candidatescentre = new Candidates(0);
};
Cell.prototype.clone = function (digit) {
var clone = new Cell();
clone._digit = this._digit;
clone._candidatescorner = this._candidatescorner.clone();
clone._candidatescentre = this._candidatescentre.clone();
clone._candidatesvisible = this._candidatesvisible.clone();
clone._given = this._given;
clone._backgroundcolor1 = this._backgroundcolor1;
clone._backgroundcolor2 = this._backgroundcolor2;
clone._backgroundcolor3 = this._backgroundcolor3;
return clone;
};
Cell.prototype.equals = function (cell) {
if (this._digit != cell._digit)
return false;
if (!this._candidatescorner.equals(cell._candidatescorner))
return false;
if (!this._candidatescentre.equals(cell._candidatescentre))
return false;
if (!this._candidatesvisible.equals(cell._candidatesvisible))
return false;
if (this._given != cell._given)
return false;
if (this._backgroundcolor1 != cell._backgroundcolor1)
return false;
if (this._backgroundcolor2 != cell._backgroundcolor2)
return false;
if (this._backgroundcolor3 != cell._backgroundcolor3)
return false;
return true;
};
Cell.prototype.getCandidatesArray = function () {
return this._candidatescorner.candidatesArray();
};
Cell.prototype.getCandidatesArrayCentre = function () {
return this._candidatescentre.candidatesArray();
};
Cell.prototype.isCandidateVisible = function (digit) {
return this._candidatesvisible.isCandidateVisible(digit);
};
Cell.prototype.convertDigitToBitmask = function () {
return this._digit == 0 ? 0 : 1 << this._digit;
};
Cell.prototype.hasSingle = function () {
return this._candidatescorner.count() == 1;
};
Cell.prototype.isGiven = function () {
return this._given;
};
Cell.prototype.isAssigned = function () {
return this._digit != 0;
};
Cell.prototype.clear = function () {
this._digit = 0; // means unassigned
this._candidatescorner = new Candidates(0);
this._candidatescentre = new Candidates(0);
this._candidatesvisible = new Candidates(0);
this._given = 0;
this._backgroundcolor1 = "";
this._backgroundcolor2 = "";
this._backgroundcolor3 = "";
};
Cell.prototype.hasCandidate = function (digit) {
return this._candidatescorner.hasCandidate(digit);
};
Cell.prototype.hasCandidateCentre = function (digit) {
return this._candidatescentre.hasCandidate(digit);
};
Cell.prototype.initCandidatesCorner = function (bitmask) {
this._candidatescorner = new Candidates(bitmask);
};
Cell.prototype.initCandidatesVisible = function (bitmask) {
this._candidatesvisible = new Candidates(bitmask);
};
Cell.prototype.updateCandidatesCorner = function (contains) {
this._candidatescorner.update(contains);
if (board1._hasAppliedLogic)
if (this._candidatescorner.count() == 2)
this._candidatescentre = new Candidates(this.getCandidatesCorner());
};
Cell.prototype.makeCandidateVisible = function (digit) {
this._candidatesvisible.addCandidate(1 << digit);
};
Cell.prototype.countCandidates = function () {
return this._candidatescorner.count();
};
Cell.prototype.addCandidateCorner = function (digit) {
this._candidatescorner.addCandidate(1 << digit);
this._candidatesvisible.addCandidate(1 << digit)
};
Cell.prototype.addCandidateCentre = function (digit) {
this._candidatescentre.addCandidate(1 << digit);
this._candidatesvisible.addCandidate(1 << digit);
};
Cell.prototype.removeCandidateCorner = function (digit) {
if (this.hasCandidate(digit)) {
this._candidatescorner.removeCandidate(1 << digit);
if (board1._hasAppliedLogic)
if (this._candidatescorner.count() == 2)
this._candidatescentre = new Candidates(this.getCandidatesCorner());
}
};
Cell.prototype.removeCandidateCentre = function (digit) {
return this._candidatescentre.removeCandidate(1 << digit);
};
var SibType = { "Row": 1, "Col": 2, "Box": 3 };
function Location(row, col) {
this.row = row;
this.col = col;
}
Location.empty = new Location(-1, -1);
Location.prototype.isEmpty = function () {
return this.row < 0; // Arbitrary, could also be col < 0
};
Location.prototype.modulo = function (n) {
if (n < 0)
return n + BoardSize;
return n % BoardSize;
};
Location.prototype.left = function () {
return new Location(this.row, this.modulo(this.col - 1));
};
Location.prototype.right = function () {
return new Location(this.row, this.modulo(this.col + 1));
};
Location.prototype.up = function () {
return new Location(this.modulo(this.row - 1), this.col);
};
Location.prototype.down = function () {
return new Location(this.modulo(this.row + 1), this.col);
};
Location.prototype.getBoxNumber = function () {
// Standard way for converting floats to integers
return 3 * Math.floor(this.row / 3) + Math.floor(this.col / 3);
};
Location.prototype.equals = function (a) {
return a.row == this.row && a.col == this.col;
};
Location.prototype.notEquals = function (a) {
return a.row != this.row || a.col != this.col;
};
// Enumerator for locations of all cells
Location.getEnumBoard = function () {
var locs = new Array();
for (var i = 0; i < BoardSize; i++)
for (var j = 0; j < BoardSize; j++)
locs.push(new Location(i, j));
return locs;
};
// Enumerator for locations of cell siblings in the same row
Location.prototype.rowSibs = function (include) {
var locs = new Array();
for (var i = 0; i < BoardSize; i++)
if (include || i != this.col)
locs.push(new Location(this.row, i));
return locs;
};
// Enumerator for locations of cell siblings in the same column
Location.prototype.colSibs = function (include) {
var locs = new Array();
for (var i = 0; i < BoardSize; i++)
if (include || i != this.row)
locs.push(new Location(i, this.col));
return locs;
};
// Enumerator for locations of cell siblings in the same box
Location.prototype.boxSibs = function (include) {
var locs = new Array();
var baseRow = 3 * Math.floor(this.row / 3);
var baseCol = 3 * Math.floor(this.col / 3);
for (var i = 0; i < BoxSize; i++) {
var r = baseRow + i;
for (var j = 0; j < BoxSize; j++) {
var c = baseCol + j;
if (include || r != this.row || c != this.col)
locs.push(new Location(r, c));
}
}
return locs;
};
Location.prototype.getSibs = function (type, include) {
switch (type) {
case SibType.Row:
return this.rowSibs(include);
case SibType.Col:
return this.colSibs(include);
case SibType.Box:
return this.boxSibs(include);
}
};
function Board() {
function MultiDimArray(rows, cols) {
var a = new Array(rows);
for (var i = 0; i < rows; i++) {
a[i] = new Array(cols);
for (var j = 0; j < cols; j++)
a[i][j] = new Cell();
}
return a;
}
this._digits = MultiDimArray(BoardSize, BoardSize);
this._hasAppliedLogic = false;
}
Board.prototype.clone = function () {
var clone = new Board();
clone._hasAppliedLogic = this._hasAppliedLogic;
clone._digits = new Array(BoardSize);
for (var i = 0; i < BoardSize; i++) {
clone._digits[i] = new Array(BoardSize);
for (var j = 0; j < BoardSize; j++)
clone._digits[i][j] = this._digits[i][j].clone();
}
return clone;
};
Board.prototype.equals = function (board) {
if (this._hasAppliedLogic != board._hasAppliedLogic)
return false;
for (var i = 0; i < BoardSize; i++)
for (var j = 0; j < BoardSize; j++)
if (!this._digits[i][j].equals(board._digits[i][j]))
return false;
return true;
};
Board.prototype.copyTo = function (target) {
target._hasAppliedLogic = this._hasAppliedLogic;
for (var i = 0; i < BoardSize; i++)
for (var j = 0; j < BoardSize; j++)
target._digits[i][j] = this._digits[i][j].clone();
};
Board.prototype.copyFrom = function (source) {
this._hasAppliedLogic = source._hasAppliedLogic;
for (var i = 0; i < BoardSize; i++) {
for (var j = 0; j < BoardSize; j++) {
this._digits[i][j]._digit = source._digits[i][j]._digit;
this._digits[i][j].setCandidatesCorner(source._digits[i][j]._candidatescorner._mask);
this._digits[i][j].setCandidatesCentre(source._digits[i][j]._candidatescentre._mask);
// Adjust version here
if (version >= "3.0")
this._digits[i][j].setCandidatesVisible(source._digits[i][j]._candidatesvisible._mask);
else
this._digits[i][j].initCandidatesVisible(0);
this._digits[i][j]._given = source._digits[i][j]._given;
this._digits[i][j]._backgroundcolor1 = source._digits[i][j]._backgroundcolor1;
this._digits[i][j]._backgroundcolor2 = source._digits[i][j]._backgroundcolor2;
this._digits[i][j]._backgroundcolor3 = source._digits[i][j]._backgroundcolor3;
}
}
};
Board.prototype.getCell = function (loc) {
return this._digits[loc.row][loc.col];
};
Board.prototype.getAppliedLogic = function () {
return this._hasAppliedLogic;
};
Board.prototype.setAppliedLogic = function (hasAppliedLogic) {
return this._hasAppliedLogic = hasAppliedLogic;
};
Board.prototype.clear = function () {
for (var i = 0; i < BoardSize; i++)
for (var j = 0; j < BoardSize; j++) {
this._digits[i][j].clear();
this._digits[i][j].setColor();
}
};
Board.prototype.reset = function () {
for (var i = 0; i < BoardSize; i++)
for (var j = 0; j < BoardSize; j++) {
var cell = this._digits[i][j];
if (cell.isGiven())
cell.setColor();
else {
cell.clear();
cell.setColor();
}
}
this.initCandidates();
};
Board.prototype.checkIsValidSibs = function (loc, digit, house) {
for (var i = 0; i < house.length; i++) {
var loc = house[i];
var cell = this.getCell(loc);
if (cell.getDigit() == digit)
return false;
}
return true;
};
Board.prototype.checkIsValid = function (loc, digit) {
if (!this.checkIsValidSibs(loc, digit, loc.rowSibs(false)))
return false;
if (!this.checkIsValidSibs(loc, digit, loc.colSibs(false)))
return false;
if (!this.checkIsValidSibs(loc, digit, loc.boxSibs(false)))
return false;
return true;
};
Board.prototype.acceptSingles = function () {
var more = false;
var locs = Location.getEnumBoard();
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var cell = this._digits[loc.row][loc.col];
if (!cell.isAssigned()) {
if (cell.countCandidates() == 0) {
cell.setColor("#ff0000");
more = false;
break;
}
else if (cell.hasSingle() && this.checkIsValid(loc, cell.getSingle())) {
var digit = cell.getSingle();
cell.setDigit(digit); // if unassigned and has the answer then assign the answer
this.updateSiblings(loc, SibType.Row, digit);
this.updateSiblings(loc, SibType.Col, digit);
this.updateSiblings(loc, SibType.Box, digit);
more = true;
}
}
}
return more;
};
Board.prototype.findCellWithFewestCandidates = function () {
var minLocation = Location.empty;
var minCount = 9;
var locs = Location.getEnumBoard();
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var cell = this.getCell(loc);
if (!cell.isAssigned()) {
var count = cell.countCandidates();
if (count < minCount) {
minLocation = loc;
minCount = count;
}
}
}
return minLocation;
};
Board.prototype.evaluateRules = function () {
// Called whenever the user wants to apply basis soduko logic or via auto solve
var locs = Location.getEnumBoard();
//Rule 1: Within a house a digit may only occur once
this._rule1(locs);
// Rule 2a: Locked Candidates (Pointing)
for (var i = 0; i < BoardSize; i += BoxSize) {
for (var j = 0; j < BoxSize; j++) {
var loc = locs[i + (j * 3 * BoardSize)];
var box = loc.getSibs(SibType.Box, true);
this._rule2a(box);
}
}
// Rule 2b: Locked Candidates (Claiming)
// in rows
for (var i = 0; i < locs.length; i += BoardSize) {
var loc = locs[i];
var house = loc.getSibs(SibType.Row, true);
this._rule2b(house, SibType.Row)
}
// in columns
for (var i = 0; i < BoardSize; i++) {
var loc = locs[i];
var house = loc.getSibs(SibType.Col, true);
this._rule2b(house, SibType.Col)
}
// Rules 3, 4, 5 and 6: Naked/Hidden Singles/pairs/triples/Quadruples
// Examine sqares first because otherwise pencil marks outside a box aren't deleted correctly
for (var i = 0; i < BoardSize; i += BoxSize)
for (var j = 0; j < BoxSize; j++)
this._rule3456(locs[i + (j * 3 * BoardSize)], SibType.Box);
for (var i = 0; i < locs.length; i += BoardSize)
this._rule3456(locs[i], SibType.Row);
for (var i = 0; i < BoardSize; i++)
this._rule3456(locs[i], SibType.Col);
};
Board.prototype.updateSiblings = function (loc, sibtype, digit) {
var locs = loc.getSibs(sibtype, false);
for (var p = 0; p < locs.length; p++) {
var subloc = locs[p];
var subcell = this.getCell(subloc);
if (!subcell.isAssigned()) {
// Remove digit in corner
subcell.removeCandidateCorner(digit);
subcell.removeCandidateCentre(digit);
}
}
}
Board.prototype.initCandidates = function () {
var locs = Location.getEnumBoard();
var cols = new Array(BoardSize);
var rows = new Array(BoardSize);
var boxes = new Array(BoardSize);
// First aggregate assigned values to rows, cols, boxes
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
// Disallow for all cells in this row
var contains = this.getCell(loc).convertDigitToBitmask();
rows[loc.row] |= contains;
cols[loc.col] |= contains;
boxes[loc.getBoxNumber()] |= contains;
}
// For each cell, aggregate the values already set in that row, col and box.
// Since the aggregate is a bitmask, the bitwise inverse of that is therefore the candidates.
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var contains = rows[loc.row] | cols[loc.col] | boxes[loc.getBoxNumber()];
var cell = this.getCell(loc);
cell.initCandidatesCorner(contains ^ 0x3FE);
cell.initCandidatesVisible(0);
}
}
Board.prototype.updateCandidatesVisibility = function () {
var locs = Location.getEnumBoard();
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var cell = this.getCell(loc);
cell.initCandidatesVisible(cell.getCandidatesCorner());
}
}
// rule 1: Within a house a digit may occur only once
Board.prototype._rule1 = function (locs) {
var cols = new Array(BoardSize);
var rows = new Array(BoardSize);
var boxes = new Array(BoardSize);
// First aggregate assigned values to rows, cols, boxes
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
// Disallow for all cells in this row
var contains = this.getCell(loc).convertDigitToBitmask();
rows[loc.row] |= contains;
cols[loc.col] |= contains;
boxes[loc.getBoxNumber()] |= contains;
}
// For each cell, aggregate the values already set in that row, col and box.
// Since the aggregate is a bitmask, the bitwise inverse of that is therefore the candidates.
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var contains = rows[loc.row] | cols[loc.col] | boxes[loc.getBoxNumber()];
var cell = this.getCell(loc);
cell.updateCandidatesCorner(contains ^ 0x3FE);
}
}
// rule 2a: Locked candidates (pointing)
Board.prototype._rule2a = function (box) {
for (var digit = 1; digit <= 9; digit++) {
var ar = new Array();
for (var m = 0; m < box.length; m++) {
var subloc = box[m];
var cell = this.getCell(subloc);
if (!cell.isAssigned())
if (cell.hasCandidate(digit))
ar.push(subloc);
}
if (ar.length == 2 || ar.length == 3) {
// examine array
//for rows
var subrow = ar[0].row;
var isEqual = true;
for (var n = 1; n < ar.length; n++) {
if (ar[n].row !== subrow) {
isEqual = false;
break;
}
}
if (isEqual) {
// remove digit from cells in row outside box
var rows = ar[0].getSibs(SibType.Row, true);
for (var n = 0; n < rows.length; n++) {
var found = false;
for (var p = 0; p < ar.length; p++) {
if (rows[n].col == ar[p].col) {
found = true;
break;
}
}
if (!found) {
var subcell = this.getCell(rows[n]);
subcell.removeCandidateCorner(digit);
subcell.removeCandidateCentre(digit);
}
}
}
// for columns
var subcol = ar[0].col;
var isEqual = true;
for (var n = 1; n < ar.length; n++) {
if (ar[n].col !== subcol) {
isEqual = false;
break;
}
}
if (isEqual) {
// remove digit from cells in column outside box
var cols = ar[0].getSibs(SibType.Col, true);
for (var n = 0; n < cols.length; n++) {
var found = false;
for (var p = 0; p < ar.length; p++) {
if (cols[n].row == ar[p].row) {
found = true;
break;
}
}
if (!found) {
var subcell = this.getCell(cols[n]);
subcell.removeCandidateCorner(digit);
subcell.removeCandidateCentre(digit);
}
}
}
}
}
}
// rule 2b: Locked candidates (claiming)
Board.prototype._rule2b = function (house, sibtype) {
for (var digit = 1; digit <= 9; digit++) {
var ar = new Array();
for (var m = 0; m < house.length; m++) {
var subloc = house[m];
var cell = this.getCell(subloc);
if (!cell.isAssigned())
if (cell.hasCandidate(digit))
ar.push(subloc);
}
if (ar.length == 2 || ar.length == 3) {
// examine array
var boxnumber = ar[0].getBoxNumber();
var isEqual = true;
for (var n = 1; n < ar.length; n++) {
if (ar[n].getBoxNumber() !== boxnumber) {
isEqual = false;
break;
}
}
if (isEqual) {
var sublocs = ar[0].getSibs(SibType.Box, true);
for (var n = 0; n < sublocs.length; n++) {
var subloc = sublocs[n];
if (sibtype == SibType.Row) {
if (subloc.row != ar[0].row) {
var subcell = this.getCell(subloc);
subcell.removeCandidateCorner(digit);
subcell.removeCandidateCentre(digit);
}
}
else {
if (subloc.col != ar[0].col) {
var subcell = this.getCell(subloc);
subcell.removeCandidateCorner(digit);
subcell.removeCandidateCentre(digit);
}
}
}
}
}
}
}
// Rule 3: Naked/Hidden Singles
// Rule 4: Naked/Hidden Pairs
// Rule 5: Naked/Hidden Triples
// Rule 6: Naked/Hidden Quadruples
Board.prototype._rule3456 = function (loc, sibtype) {
var cell = this.getCell(loc);
var house = loc.getSibs(sibtype, true);
// arDigits contains the allowed digits to be processed
var arDigits = new Array();
// for a better perfomance arCandidates represents a house during rule evaluation
var arCandidates = new Array();
var allowed = 0;
for (var p = 0; p < house.length; p++) {
var subloc = house[p];
var subcell = this.getCell(subloc);
if (!subcell.isAssigned()) {
arCandidates.push([p, subcell.getCandidatesCorner()]);
allowed |= subcell.getCandidatesCorner();
}
}
for (var digit = 1; digit <= BoardSize; digit++) {
if ((allowed & (1 << digit)) != 0)
arDigits.push([digit, true]);
}
// Rule 3: Naked/hidden singles
level = 1;
for (var i = 0; i < arDigits.length; i++) {
if (arDigits[i][1]) {
// i represents combination of 1 digit, a possible single
this._rule3456_2(level, house, arCandidates, arDigits, i);
}
}
// Rule 4: Naked/hidden pairs
level = 2;
for (var i = 0; i < arDigits.length; i++) {
if (arDigits[i][1]) {
for (var j = i + 1; j < arDigits.length; j++) {
if (arDigits[j][1]) {
// i, j represents combination of 2 digits, a possible pair
this._rule3456_2(level, house, arCandidates, arDigits, i, j);
}
}
}
}
// Rule 5: Naked/hidden triples
level = 3;
for (var i = 0; i < arDigits.length; i++) {
if (arDigits[i][1]) {
for (var j = i + 1; j < arDigits.length; j++) {
if (arDigits[j][1]) {
for (var k = j + 1; k < arDigits.length; k++) {
if (arDigits[k][1]) {
// i, j and k represents combination of 3 digits, a possible triple
this._rule3456_2(level, house, arCandidates, arDigits, i, j, k);
}
}
}
}
}
}
// Rule 6: Naked/hidden quadruples
level = 4;
for (var i = 0; i < arDigits.length; i++) {
if (arDigits[i][1]) {
for (var j = i + 1; j < arDigits.length; j++) {
if (arDigits[j][1]) {
for (var k = j + 1; k < arDigits.length; k++) {
if (arDigits[k][1]) {
for (var l = k + 1; l < arDigits.length; l++) {
if (arDigits[l][1]) {
// i, j,k and l represents combination of 4 digits, a possible quadruple
this._rule3456_2(level, house, arCandidates, arDigits, i, j, k, l);
}
}
}
}
}
}
}
}
}
Board.prototype._rule3456_2 = function (level, house, arCandidates, arDigits, i = 0, j = 0, k = 0, l = 0) {
if (level > 2) {
var count = 0;
for (var n = 0; n < arDigits.length; n++)
if (arDigits[n][1])
count++;
if (count <= level)
// examination not relevant when there are no candidates outside possible triple or quadruple with status true
return;
}
var ar0 = new Array();
var ar1 = new Array();
// arCandidates represents the candidates within the house
// p points to location in house
for (var p = 0; p < arCandidates.length; p++) {
var mask = 0;
var count = 0;
if (level > 0) {
if ((arCandidates[p][1] & (1 << arDigits[i][0])) != 0) {
mask |= (1 << arDigits[i][0]);
count++;
}
}
if (level > 1) {
if ((arCandidates[p][1] & (1 << arDigits[j][0])) != 0) {
mask |= (1 << arDigits[j][0]);
count++;
}
}
if (level > 2) {
if ((arCandidates[p][1] & (1 << arDigits[k][0])) != 0) {
mask |= (1 << arDigits[k][0]);
count++;
}
}
if (level > 3) {
if ((arCandidates[p][1] & (1 << arDigits[l][0])) != 0) {
mask |= (1 << arDigits[l][0]);
count++;
}
}
if ((level <= 2 && count == level) || (level > 2 && count >= 2)) {
if ((mask | arCandidates[p][1]) == mask)
ar0.push(arCandidates[p][0]);
else
ar1.push(arCandidates[p][0]);
}
}
if (ar0.length == level || ar0.length + ar1.length == level) {
// Check whether candidates doesn't exist outside possible single, pair, triple or quadruple
var found = false;
if (ar0.length == level) {
// naked single, pair, triple or quadruple
}
else {
ar0 = ar0.concat(ar1);
for (var p = 0; p < house.length; p++) {
var skip = false;
if (level > 0 && p == ar0[0])
skip = true;
if (level > 1 && p == ar0[1])
skip = true;
if (level > 2 && p == ar0[2])
skip = true;
if (level > 3 && p == ar0[3])
skip = true;
if (skip) {
}
else {
subcell = this.getCell(house[p]);
if (level > 0) {
if (!subcell.isAssigned() && subcell.hasCandidate(arDigits[i][0])) {
found = true;
break;
}
}
if (level > 1) {
if (!subcell.isAssigned() && subcell.hasCandidate(arDigits[j][0])) {
found = true;
break;
}
}
if (level > 2) {
if (!subcell.isAssigned() && subcell.hasCandidate(arDigits[k][0])) {
found = true;
break;
}
}
if (level > 3) {
if (!subcell.isAssigned() && subcell.hasCandidate(arDigits[l][0])) {
found = true;
break;
}
}
}
}
}
if (!found) {
for (var p = 0; p < house.length; p++) {
subcell = this.getCell(house[p]);
var skip = false;
if (level > 0 && p == ar0[0])
skip = true;
if (level > 1 && p == ar0[1])
skip = true;
if (level > 2 && p == ar0[2])
skip = true;
if (level > 3 && p == ar0[3])
skip = true;
if (skip) {
var mask1 = new Candidates();
if (level > 0)
mask1.addCandidate(1 << arDigits[i][0]);
if (level > 1)
mask1.addCandidate(1 << arDigits[j][0]);
if (level > 2)
mask1.addCandidate(1 << arDigits[k][0]);
if (level > 3)
mask1.addCandidate(1 << arDigits[l][0]);
var mask2 = mask1.clone();
mask2.logicalAnd(subcell.getCandidatesCorner());
var count = mask2.count();
subcell.removeAllCandidatesCentre();
var ar = subcell.getCandidatesArray();
for (var q = 0; q < ar.length; q++) {
if (mask1.hasCandidate(ar[q])) {
if (count < 3)
subcell.addCandidateCentre(ar[q]);
}
else
subcell.removeCandidateCorner(ar[q]);
}
// update arCandidates
for (var q = 0; q < arCandidates.length; q++) {
if (arCandidates[q][0] == p) {
arCandidates[q][1] = subcell.getCandidatesCorner();
break;
}
}
}
else {
// remove candidates in corner
if (level > 0)
subcell.removeCandidateCorner(arDigits[i][0]);
if (level > 1)
subcell.removeCandidateCorner(arDigits[j][0]);
if (level > 2)
subcell.removeCandidateCorner(arDigits[k][0]);
if (level > 3)
subcell.removeCandidateCorner(arDigits[l][0]);
for (var q = 0; q < arCandidates.length; q++) {
if (arCandidates[q][0] == p) {
if (level > 0)
arCandidates[q][1] ^ (1 << arDigits[i][0]);
if (level > 1)
arCandidates[q][1] ^ (1 << arDigits[j][0]);
if (level > 2)
arCandidates[q][1] ^ (1 << arDigits[k][0]);
if (level > 3)
arCandidates[q][1] ^ (1 << arDigits[l][0]);
break;
}
}
}
}
if (level > 0)
arDigits[i][1] = false;
if (level > 1)
arDigits[j][1] = false;
if (level > 2)
arDigits[k][1] = false;
if (level > 3)
arDigits[l][1] = false;
}
}
}
Board.prototype.autoSolve = function (loc, digit) { // empty Location allowed
var isSolved = false;
if (!loc.isEmpty()) { // assign a digit to a location if provided
var cell = this.getCell(loc);
if (!cell.hasCandidate(digit))
throw "Internal error.";
cell.setDigit(digit);
this.updateSiblings(loc, SibType.Row, digit);
this.updateSiblings(loc, SibType.Col, digit);
this.updateSiblings(loc, SibType.Box, digit);
}
while (true) {
this.evaluateRules();
if (!this.acceptSingles()) // keep doing deterministic answers
break;
}
if (this.isSolved())
isSolved = true;
else {
// No deterministic solutions,
// find cell with the fewest candidates and try each one in turn until success
var locChoice = this.findCellWithFewestCandidates();
if (!locChoice.isEmpty()) {
var cell = this.getCell(locChoice);
var Candidates = cell.getCandidatesArray();
for (var i = 0; i < Candidates.length; i++) {
var val = Candidates[i];
var newBoard = this.clone();
if (newBoard.autoSolve(locChoice, val) == true) {
newBoard.copyTo(this);
isSolved = true;
break;
}
}
}
}
return isSolved
};
Board.prototype.isSolved = function () {
var locs = Location.getEnumBoard();
var isSolved = true;
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var cell = this.getCell(loc);
if (!cell.isAssigned()) {
isSolved = false;
break;
}
}
return isSolved
}
Board.prototype.setString = function (value) {
// Assumes that a dot or a zero represents an empty cell
value = value.substring(0, 81);
var n = 0;
for (var row = 0; row < BoardSize; row++)
for (var col = 0; col < BoardSize; col++) {
var ch = parseInt(value.charAt(n++)); // converts '0' to 0 etc
var cell = this._digits[row][col];
cell.setGiven(!isNaN(ch) ? ch : 0);
}
return true;
};
Board.prototype.setGiven = function () {
for (var row = 0; row < BoardSize; row++)
for (var col = 0; col < BoardSize; col++) {
var cell = this._digits[row][col];
cell.setGiven(cell._digit);
}
};
// Javascript doesn't have 'contains' so added here for later readability
Array.prototype.contains = function (element) {
for (var i = 0; i < this.length; i++) {
if (this[i] == element) {
return true;
}
}
return false;
}
</script>
</head>
<body>
<div id='sudoku'>
<div id='banner'>
<table style="width:541px">
<tr>
<td><span id="big">Sudoku Explorer</span></td>
<td style="text-align:right"><span id="clock" class="clock">0:00:00</span></td>
</tr>
</table>
</div>
<div id='main'>
<table>
<tr>
<td>
<canvas id="canvas1" width="541" height="541">Canvas is not supported by this browser.</canvas>
<br/>
<canvas id="canvas2" width="541" height="62" title="Click/tap to set the currently selected digit or color 
Double click/tap in corner mode to see all candidates">Canvas is not supported by this browser.</canvas>
<br/>
<table>
<tr>
<td><button id="btnNormal" onclick="normal()" title="switch to normal big digit mode" >Normal</button><br/></td>
<td><button id="btnCorner" onclick="corner()" title="switch to corner pencil marks" >Corner</button><br/></td>
<td><button id="btnCentre" onclick="centre()" title="switch to center pencil marks" >Centre</button><br/></td>
<td><button id="btnColor" onclick="color()" title="switch to color mode" >Color</button><br/></td>
</tr>
<tr>
<td><button id="btnUndo" onclick="undo()" title="Undoes the last user action except load, clear and reset">Undo</button><br/></td>
<td><button id="btnRedo" onclick="redo()" title="Redoes the last undo">Redo</button><br/></td>
<td><button id="btnAccept" onclick="applyLogic()" title="Applies standard Sudoku logic" >Apply logic</button><br/></td>
<td><button id="btnSolve" onclick="solve()" title="Solves your puzzle if possible" >Solve</button><br/></td>
</tr>
<tr>
<td><button id="btnCheck" onclick="check()" title="Checks your solution" >Check</button><br/></td>
<td><button id="btnReset" onclick="confirmReset()" onblur="noReset()" title="Clears all user entered cells. The givens are NOT cleared.">Reset</button><br/></td>
<td><button id="btnHint" onclick="hint()" title="Gives the solution for the currently selected cells" >Hint</button><br/></td>
<td><button id="btnDelete" onclick="deletedigit()" title="Deletes the assigned value of the currently selected cells" >Delete</button><br/></td>
</tr>
<tr>
<td><button id="btnClear" onclick="confirmClear()" onblur="noClear()" title="Clears all cells including givens" >Clear</button><br/></td>
<td><button id="btnLoad" onclick="load()" title="Set givens">Load</button><br/></td>
<td><input id="importfile" type="file" style="display:none" onchange="onImport()">
<button id="importfileex" onclick="importfile.click()" title="Import Sudoku file from your file system">Import file</button></td>
<td><button id="btnInfo" onclick="info()" title="Help for using this app" >Help</button><br/></td>
</tr>
</table>
<label for="dropbox" style="font-size: 0.9em;">Dropbox:</label>
<input id="dropbox" onchange="loadString()" title="Copy and paste Sudoku string here" style="width: 470px; height: 30px; background-color: #faf0e6; margin-top: 10px;"/>
</td>
</tr>
</table>
<script type="text/javascript" >
// Adjust version here
var version = "3.0";
var CellSize = 60;
var SubCellSize = 18;
var canvas1 = document.getElementById("canvas1");
var canvas2 = document.getElementById("canvas2");
var dropbox = document.getElementById("dropbox");
var board1 = new Board();
var undostack = new Undostack();
var colors = ["#fcaca3", "#f8c8a0", "#ffe559", "Yellow", "#ffffe0", "GreenYellow", "PaleTurquoise", "LightBlue", "#f5b4f5"];
var selectRow = 0;
var selectCol = 0;
var selectedLocations = Array();
var mode = 1;
var notLoaded = true;
var elapsedTime = 0;
var prevTime = new Date().getTime();
var startDate = new Date();
var clock = setInterval(updateTime, 1000);
// Converts global co-ords used in mouse events to relative to element
function relMouseCoords(event) {
var totalOffsetX = 0;
var totalOffsetY = 0;
var canvasX = 0;
var canvasY = 0;
var currentElement = this;
do {
totalOffsetX += currentElement.offsetLeft;
totalOffsetY += currentElement.offsetTop;
}
while (currentElement = currentElement.offsetParent)
canvasX = event.pageX - totalOffsetX;
canvasY = event.pageY - totalOffsetY;
return { x: canvasX, y: canvasY }
}
HTMLCanvasElement.prototype.relMouseCoords = relMouseCoords;
// Converts global co-ords used in touchscreen events to relative to element
function relTouchCoords(event) {
var totalOffsetX = 0;
var totalOffsetY = 0;
var canvasX = 0;
var canvasY = 0;
var currentElement = this;
do {
totalOffsetX += currentElement.offsetLeft;
totalOffsetY += currentElement.offsetTop;
}
while (currentElement = currentElement.offsetParent)
canvasX = event.targetTouches[0].pageX - totalOffsetX;
canvasY = event.targetTouches[0].pageY - totalOffsetY;
return { x: canvasX, y: canvasY }
}
HTMLCanvasElement.prototype.relTouchCoords = relTouchCoords;
function drawCanvas(noSelect = false) {
// General accepted way for clearing the canvas
canvas1.width = canvas1.width;
drawGrid();
drawCells(noSelect);
}
function drawGrid() {
// Only called once
var context = canvas1.getContext('2d');
context.strokeStyle = '#696969';
for (var i = 0; i <= BoardSize; i++) {
context.beginPath();
var thick = i % 3 == 0;
// Draw vertical lines
context.lineWidth = thick ? 2 : 1;
context.moveTo(i * CellSize + 0.5, 0.5);
context.lineTo(i * CellSize + 0.5, BoardSize * CellSize + 0.5);
// Draw horizontal lines
context.moveTo(0.5, i * CellSize + 0.5);
context.lineTo(BoardSize * CellSize + 0.5, i * CellSize + 0.5);
context.stroke();
}
}
function drawCells(noSelect) {
var context = canvas1.getContext('2d');
context.font = "12pt Calibri"; // small text
context.textAlign = "center";
context.textBaseline = "middle";
var normalColor = "#aaaaaa";
var singleColor = "#ff143c";
// Draw background for selected cell
for (var row = 0; row < BoardSize; row++)
for (var col = 0; col < BoardSize; col++) {
// Draw background of selected cell
var cell = board1.getCell(new Location(row, col));
var margin = 2;
var x = col * CellSize + margin + 0.5;
var y = row * CellSize + margin + 0.5;
var width = CellSize - 2 * margin;
var height = CellSize - 2 * margin;
drawCellBackground(cell, context, row, col, x, y, width, height, margin);
if (!noSelect) {
context.beginPath();
context.rect(col * CellSize + margin + 0.5, row * CellSize + margin + 0.5, CellSize - 2 * margin, CellSize - 2 * margin);
for (var i = 0; i < selectedLocations.length; i++) {
var loc = selectedLocations[i];
if (row == loc.row && col == loc.col) {
context.fillStyle = "#ffe4e1"; // LightPink
context.fill();
}
}
}
}
drawPencilMarks(context);
// Draw digits last
context.font = "32pt Calibri";
context.textAlign = "center";
context.textBaseline = "middle";
var normalForeColor = "#191929";
var sameDigitForeColor = "#F91919";
context.fillStyle = normalForeColor; // text color - dark
for (var row = 0; row < BoardSize; row++)
for (var col = 0; col < BoardSize; col++) {
var cell = board1.getCell(new Location(row, col));
var x = (col + 0.5) * CellSize; // center of cell for textAlign center, textBaseline middle
var y = (row + 0.5) * CellSize;
var digit = cell.getDigit();
if (digit != 0) {
context.fillStyle = cell.isGiven() ? "#2200aa" : "#696969"; // show "givens" in a darker color
context.fillText(digit, x, y);
}
}
}
// Action om mousemove
function redrawCell(row, col) {
var context = canvas1.getContext('2d');
context.font = "12pt Calibri"; // small text
context.textAlign = "center";
context.textBaseline = "middle";
var normalColor = "#aaaaaa";
var singleColor = "#ff143c";
// Draw colored background of selected cell
var margin = 2;
context.beginPath();
context.rect(col * CellSize + margin + 0.5, row * CellSize + margin + 0.5, CellSize - 2 * margin, CellSize - 2 * margin);
context.fillStyle = "#ffe4e1";
context.fill();
drawPencilMarks(context);
// Draw digits last
context.font = "32pt Calibri";
context.textAlign = "center";
context.textBaseline = "middle";
var normalForeColor = "#191929";
var sameDigitForeColor = "#F91919";
context.fillStyle = normalForeColor;
var cell = board1.getCell(new Location(row, col));
var x = (col + 0.5) * CellSize; // center of cell for textAlign center, textBaseline middle
var y = (row + 0.5) * CellSize;
var digit = cell.getDigit();
if (digit != 0) {
context.fillStyle = cell.isGiven() ? "#2200aa" : "#696969";
context.fillText(digit, x, y);
}
}
function drawPencilMarks(context) {
context.font = "12pt Calibri"; // small text
context.textAlign = "center";
context.textBaseline = "middle";
var normalColor = "#333333";
var singleColor = "#ff143c";
context.fillStyle = "#999999"; // text color - light
// Draw allowed values in corner and centre
// positions for pencil marks in corner
var pos = [1, 3, 7, 9, 2, 8, 4, 6, 1];
for (var row = 0; row < BoardSize; row++) {
for (var col = 0; col < BoardSize; col++) {
var cell = board1.getCell(new Location(row, col));
if (!cell.isAssigned()) {
// pencil marks in corner
context.fillStyle = normalColor;
var candidates = cell.getCandidatesArray();
var n = 0;
for (var i = 0; i < candidates.length; i++) {
var val = candidates[i];
if (cell.isCandidateVisible(val)) {
var x = (col + 0.5) * CellSize; // center of cell for textAlign center, textBaseline middle
var y = (row + 0.5) * CellSize;
var subRow = Math.floor((pos[n] - 1) / 3) - 1;
var subCol = Math.floor((pos[n] - 1) % 3) - 1;
x += subCol * SubCellSize;
y += subRow * SubCellSize;
context.fillText(val, x, y);
n++;
}
}
// pencil marks in centre
context.fillStyle = singleColor;
var candidates = cell.getCandidatesArrayCentre();
var str = "";
for (var i = 0; i < candidates.length; i++) {
if (cell.isCandidateVisible(candidates[i])) {
var val = candidates[i];
str += val;
}
}
var x = (col + 0.5) * CellSize; // center of cell for textAlign center, textBaseline middle
var y = (row + 0.5) * CellSize;
var subRow = 0;
var subCol = 0;
x += subCol * SubCellSize;
y += subRow * SubCellSize;
context.fillText(str, x, y);
}
}
}
}
function drawCellBackground(cell, ctx, row, col, x, y, width, height, margin) {
if (cell.getColor(3) === "")
if (cell.getColor(2) === "") {
ctx.beginPath();
ctx.fillStyle = cell.getColor(1);
ctx.rect(col * CellSize + margin + 0.5, row * CellSize + margin + 0.5, CellSize - 2 * margin, CellSize - 2 * margin);
ctx.fill();
}
else {
// split
ctx.beginPath();
ctx.moveTo(x,y);
ctx.lineTo(x + width,y);
ctx.lineTo(x, y + height);
ctx.lineTo(x, y);
ctx.fillStyle = cell.getColor(1);
ctx.fill();
ctx.beginPath();
ctx.moveTo(x + width, y);
ctx.lineTo(x + width, y + height);
ctx.lineTo(x, y + height);
ctx.lineTo(x + width, y);
ctx.fillStyle = cell.getColor(2);
ctx.fill();
}
else {
// double split
ctx.beginPath();
ctx.moveTo(x, y);
ctx.lineTo(x + width / 2, y);
ctx.lineTo(x + width / 2, y + height / 2);
ctx.lineTo(x, y + height);
ctx.lineTo(x, y);
ctx.fillStyle = cell.getColor(1);
ctx.fill();
ctx.beginPath();
ctx.moveTo(x + width / 2, y + height / 2);
ctx.lineTo(x + width, y + height);
ctx.lineTo(x, y + height);
ctx.lineTo(x + width / 2, y + height / 2);
ctx.fillStyle = cell.getColor(2);
ctx.fill();
ctx.beginPath();
ctx.moveTo(x + width / 2, y);
ctx.lineTo(x + width, y);
ctx.lineTo(x + width, y + height);
ctx.lineTo(x + width / 2, y + height / 2);
ctx.moveTo(x + width / 2, y);
ctx.fillStyle = cell.getColor(3);
ctx.fill();
}
}
function moveSelection(row, col) {
selectRow += row;
selectCol += col;
if (selectRow < 0)
selectRow = 8;
else if (selectRow > 8)
selectRow = 0;
if (selectCol < 0)
selectCol = 8;
else if (selectCol > 8)
selectCol = 0;
selectedLocations.push(new Location(selectRow, selectCol));
drawCanvas();
}
function setDigitInCell(digit) {
for (var i = 0; i < selectedLocations.length; i++) {
var loc = selectedLocations[i];
var cell = board1.getCell(new Location(loc.row, loc.col));
switch (mode) {
case 1: // normal, digits
if (cell.isGiven())
break;
cell.setDigit(digit);
board1.updateSiblings(loc, SibType.Row, digit);
board1.updateSiblings(loc, SibType.Col, digit);
board1.updateSiblings(loc, SibType.Box, digit);
break;
case 2: // corner pencil marks
if (cell.isGiven())
break;
if (cell.hasCandidate(digit)) {
if (cell.isCandidateVisible(digit)) {
cell.removeCandidateCorner(digit);
cell.removeCandidateCentre(digit);
}
else
// make visible
cell.makeCandidateVisible(digit);
}
else {
cell.addCandidateCorner(digit);
}
break;
case 3: // centre pencil marks
if (cell.isGiven())
break;
if (cell.hasCandidate(digit)) {
if (cell.isCandidateVisible(digit)) {
if (cell.hasCandidateCentre(digit)) {
cell.removeCandidateCorner(digit);
cell.removeCandidateCentre(digit);
}
else {
if (cell.getCandidatesCentre() == 0) {
cell.removeAllCandidatesCorner();
cell.addCandidateCorner(digit);
}
cell.addCandidateCentre(digit);
}
}
else {
if (cell.hasCandidateCentre(digit)) {
}
else {
cell.addCandidateCentre(digit);
}
cell.makeCandidateVisible(digit);
}
}
else {
cell.addCandidateCorner(digit);
cell.addCandidateCentre(digit);
cell.makeCandidateVisible(digit);
}
break;
}
}
autoSave(board1);
undostack.push(board1, false);
drawCanvas();
}
function setColorInCell(digit) {
var color = digit - 1;
for (var i = 0; i < selectedLocations.length; i++) {
var loc = selectedLocations[i];
var cell = board1.getCell(new Location(loc.row, loc.col));
cell.setColor(colors[color]);
}
autoSave(board1);
undostack.push(board1);
drawCanvas(true);
}
function clearColors(digit) {
var color = digit - 1;
for (var row = 0; row < BoardSize; row++) {
for (var col = 0; col < BoardSize; col++) {
var cell = board1.getCell(new Location(row, col));
cell.setColor(colors[color], "noSplit");
}
}
autoSave(board1);
undostack.push(board1);
drawCanvas(true);
}
function markCells(digit) {
var found = false;
for (var row = 0; row < BoardSize; row++) {
for (var col = 0; col < BoardSize; col++) {
var cell = board1.getCell(new Location(row, col));
if (cell.isAssigned()) {
if (mode == 1 && cell.getDigit() == digit) {
found = true;
cell.setColor("#ffdead"); // NavajoWhite
}
}
else {
if (mode == 2 && cell.hasCandidate(digit) && cell.isCandidateVisible(digit)) {
found = true;
cell.setColor("#ffdead"); // NavajoWhite
}
}
}
}
if (found) {
undostack.push(board1);
drawCanvas(true);
}
else
drawCanvas();
}
function canvasMouseDown(ev) {
var x = ev.pageX - canvas1.offsetLeft;
var y = ev.pageY - canvas1.offsetTop;
var coords = canvas1.relMouseCoords(ev);
var loc = new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize));
if (!event.ctrlKey)
selectedLocations = Array();
var found = false;
for (var i = 0; i < selectedLocations.length; i++) {
var loc2 = selectedLocations[i];
if (loc2.row == loc.row && loc2.col == loc.col) {
found = true;
break;
}
}
if (!found)
selectedLocations.push(new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize)));
selectRow = Math.floor(coords.y / CellSize);
selectCol = Math.floor(coords.x / CellSize);
drawCanvas();
}
function canvasTouchStart(ev) {
var x = ev.targetTouches[0].pageX - canvas1.offsetLeft;
var y = ev.targetTouches[0].pageY - canvas1.offsetTop;
var coords = canvas1.relTouchCoords(ev);
var loc = new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize));
var found = false;
selectedLocations = Array();
for (var i = 0; i < selectedLocations.length; i++) {
var loc2 = selectedLocations[i];
if (loc2.row == loc.row && loc2.col == loc.col) {
found = true;
break;
}
}
if (!found)
selectedLocations.push(new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize)));
selectRow = Math.floor(coords.y / CellSize);
selectCol = Math.floor(coords.x / CellSize);
drawCanvas();
}
function canvasMouseMove(ev) {
var x = ev.pageX - canvas1.offsetLeft;
var y = ev.pageY - canvas1.offsetTop;
var coords = canvas1.relMouseCoords(ev);
var loc = new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize));
var found = false;
// Alas necessary
if (loc.row > 8)
loc.row = 8;
if (loc.col > 8)
loc.col = 8;
// Doesn't seam to be necessary
for (var i = 0; i < selectedLocations.length; i++) {
var loc2 = selectedLocations[i];
if (loc2.row == loc.row && loc2.col == loc.col) {
found = true;
break;
}
}
if (!found)
selectedLocations.push(new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize)));
selectRow = Math.floor(coords.y / CellSize);
selectCol = Math.floor(coords.x / CellSize);
redrawCell(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize));
}
function canvasTouchMove(ev) {
var x = ev.targetTouches[0].pageX - canvas1.offsetLeft;
var y = ev.targetTouches[0].pageY - canvas1.offsetTop;
var coords = canvas1.relTouchCoords(ev);
var loc = new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize));
var found = false;
if (loc.row > 8)
loc.row = 8;
if (loc.col > 8)
loc.col = 8;
for (var i = 0; i < selectedLocations.length; i++) {
var loc2 = selectedLocations[i];
if (loc2.row == loc.row && loc2.col == loc.col) {
found = true;
break;
}
}
if (!found)
selectedLocations.push(new Location(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize)));
selectRow = Math.floor(coords.y / CellSize);
selectCol = Math.floor(coords.x / CellSize);
redrawCell(Math.floor(coords.y / CellSize), Math.floor(coords.x / CellSize));
}
canvas1.addEventListener("mousedown", function(e){
canvasMouseDown(e);
this.addEventListener("mousemove", canvasMouseMove);
});
canvas1.addEventListener("touchstart", function(e){
e.preventDefault();
canvasTouchStart(e);
this.addEventListener("touchmove", canvasTouchMove);
});
canvas1.addEventListener("mouseup", function(e){
this.removeEventListener("mousemove", canvasMouseMove);
});
canvas1.addEventListener("touchend", function(e){
this.removeEventListener("touchmove", canvasTouchMove);
});
// Specific for IOS: Disable zoom in and zoom out
var lastTouchEnd = 0;
document.documentElement.addEventListener('touchend', function (e) {
var now = new Date().getTime();
if (now - lastTouchEnd <= 350) {
e.preventDefault();
}
lastTouchEnd = now;
}, false);
document.addEventListener("keydown", function(e){
if (["ArrowUp", "ArrowDown", "ArrowLeft", "ArrowRight"].indexOf(e.code) > -1) {
e.preventDefault();
}
}, false);
document.onkeydown = function (ev) {
switch (ev.keyCode) {
case 37: // left arrow
case 65: // a
if (!event.ctrlKey)
selectedLocations = Array();
moveSelection(0, -1);
break;
case 38: // up arrow
case 87: // w
if (!event.ctrlKey)
selectedLocations = Array();
moveSelection(-1, 0);
break;
case 39: // right arrow
case 68: // d
if (!event.ctrlKey)
selectedLocations = Array();
moveSelection(0, 1);
break;
case 40: // down arrow
case 83: // s
if (!event.ctrlKey)
selectedLocations = Array();
moveSelection(1, 0);
break;
case 16: // Shift key
break;
case 17: // Ctrl key
// selectedLocations = Array();
break;
case 89:
if (event.ctrlKey) // Ctrl + y pressed
redo();
break;
case 90: // z switch to mode Normal
if (event.ctrlKey) // Ctrl + z pressed
undo();
else
normal();
break;
case 88: // x switch to mode Corner
corner();
break;
case 67: // c switch to mode Centre
centre();
break;
case 86: // v switch to mode Color
// 15-11-2021
if (!event.ctrlKey)
color();
break;
case 32: // spacebar go to next mode
if (event.ctrlKey) {
switch (mode) {
case 1:
color();
break;
case 2:
normal();
break;
case 3:
corner();
break;
case 4:
centre();
break;
}
}
else {
switch (mode) {
case 1:
corner();
break;
case 2:
centre();
break;
case 3:
color();
break;
case 4:
normal();
break;
}
}
break;
case 46: // Del Delete
case 8: // Backspace
if (mode < 4)
setDigitInCell(0);
break;
default:
var key = Number(ev.keyCode);
var digit = key >= 96 ? key - 96 : key - 48;// handle keypad digits as well
if (digit >= 0 && digit <= 9)
if (mode < 4) {
var modeOld = mode;
if (mode == 2 && event.shiftKey)
mode = 1;
if (mode == 3 && event.ctrlKey)
mode = 1;
setDigitInCell(digit);
mode = modeOld;
}
else {
var modeOld = mode;
if (event.shiftKey)
if (event.ctrlKey)
mode = 1;
setDigitInCell(digit);
mode = modeOld;
}
break;
}
}
function normal() {
mode = 1;
numericKeys();
document.getElementById("btnNormal").style.backgroundColor = "#1e90ff";
document.getElementById("btnCorner").style.backgroundColor = "#bbbbbb";
document.getElementById("btnCentre").style.backgroundColor = "#bbbbbb";
document.getElementById("btnColor").style.backgroundColor = "#bbbbbb";
drawCanvas();
}
function corner() {
mode = 2;
numericKeys();
document.getElementById("btnNormal").style.backgroundColor = "#bbbbbb";
document.getElementById("btnCorner").style.backgroundColor = "#1e90ff";
document.getElementById("btnCentre").style.backgroundColor = "#bbbbbb";
document.getElementById("btnColor").style.backgroundColor = "#bbbbbb";
drawCanvas();
}
function centre() {
mode = 3;
numericKeys();
document.getElementById("btnNormal").style.backgroundColor = "#bbbbbb";
document.getElementById("btnCorner").style.backgroundColor = "#bbbbbb";
document.getElementById("btnCentre").style.backgroundColor = "#1e90ff";
document.getElementById("btnColor").style.backgroundColor = "#bbbbbb";
drawCanvas();
}
function color() {
mode = 4;
colorKeys();
document.getElementById("btnNormal").style.backgroundColor = "#bbbbbb";
document.getElementById("btnCorner").style.backgroundColor = "#bbbbbb";
document.getElementById("btnCentre").style.backgroundColor = "#bbbbbb";
document.getElementById("btnColor").style.backgroundColor = "#1e90ff";
drawCanvas();
}
function undo() {
if (undostack.undo(board1)) {
autoSave(board1);
drawCanvas();
}
}
function redo() {
if (undostack.redo(board1)) {
drawCanvas();
}
}
function applyLogic() {
board1.updateCandidatesVisibility();
board1.evaluateRules();
board1.acceptSingles();
board1._hasAppliedLogic = true;
autoSave(board1);
undostack.push(board1);
drawCanvas();
}
function solve() {
board1.autoSolve(Location.empty, 0);
undostack.push(board1);
drawCanvas();
}
function check() {
var isValid = true;
var locs = Location.getEnumBoard();
for (var i = 0; i < locs.length; i++) {
var loc = locs[i];
var cell = board1.getCell(loc);
if (cell.getDigit() == 0) {
cell.setColor("#ff0000");
isValid = false;
}
else {
if (!board1.checkIsValid(loc, cell.getDigit())) {
cell.setColor("#ff0000");
isValid = false;
}
}
}
undostack.push(board1);
drawCanvas();
if (isValid) {
clearInterval(clock);
alert('It seems you have solved the puzzle');
}
}
function reset() {
clearUndo();
board1.reset();
board1.setAppliedLogic(false);
clearInterval(clock);
startDate = new Date();
clock = setInterval(updateTime, 1000);
undostack.push(board1); // extra pushboard for undo
normal();
drawCanvas();
}
function confirmReset() {
var btn = document.getElementById("btnReset");
if (btn.innerText == "Reset") {
btn.innerText = "Confirm?"
btn.style.backgroundColor = "#ff0000";
}
else {
btn.innerText = "Reset"
btn.style.backgroundColor = "#bbbbbb";
reset();
}
}
function noReset() {
var btn = document.getElementById("btnReset");
btn.innerText = "Reset"
btn.style.backgroundColor = "#bbbbbb";
}
function hint() {
// First check if we had calculated a solution, if not do so now
var old = board1.getAppliedLogic();
board1.setAppliedLogic(false);
solution = board1.clone();
if (solution.autoSolve(Location.empty, 0)) {
// There is a solution to the board from its current state
for (var n = 0; n < selectedLocations.length; n++) {
var loc = selectedLocations[n];
var solCell = solution.getCell(new Location(loc.row, loc.col));
if (!solCell.isGiven()) {
var cell = board1.getCell(new Location(loc.row, loc.col))
var digit = solCell.getDigit();
cell.setDigit(digit);
// Remove digit from siblings
board1.updateSiblings(loc, SibType.Row, digit);
board1.updateSiblings(loc, SibType.Col, digit);
board1.updateSiblings(loc, SibType.Box, digit);
undostack.push(board1);
}
}
}
board1.setAppliedLogic(old);
drawCanvas();
}
function deletedigit() {
for (var n = 0; n < selectedLocations.length; n++) {
var loc = selectedLocations[n];
var cell = board1.getCell(new Location(loc.row, loc.col));
cell.setDigit(0);
}
autoSave(board1);
undostack.push(board1);
drawCanvas();
}
function clearGame() {
clearUndo();
board1.clear();
clearInterval(clock);
document.getElementById("clock").innerText = "0:00:00";
undostack.push(board1); // extra pushboard for undo
normal();
drawCanvas();
}
function confirmClear() {
var btn = document.getElementById("btnClear");
if (btn.innerText == "Clear") {
btn.innerText = "Confirm?"
btn.style.backgroundColor = "#ff0000";
}
else {
btn.innerText = "Clear"
btn.style.backgroundColor = "#bbbbbb";
clearGame();
}
}
function noClear() {
var btn = document.getElementById("btnClear");
btn.innerText = "Clear"
btn.style.backgroundColor = "#bbbbbb";
}
function load() {
if (dropbox.value === "") {
board1.setGiven();
board1.initCandidates();
board1.setAppliedLogic(false);
undostack.push(board1); // extra pushboard for undo
}
else {
loadString();
}
clearInterval(clock);
startDate = new Date();
clock = setInterval(updateTime, 1000);
normal();
drawCanvas();
}
function loadString() {
board1.clear();
board1.setString(dropbox.value);
dropbox.value = "";
board1.setAppliedLogic(false);
autoSave(board1);
undostack.push(board1); // extra pushboard for undo
}
function onImport(event) {
var fileReader = new FileReader();
fileReader.onload = function(event) {
board1.clear();
board1.setString(event.target.result);
board1.setAppliedLogic(false);
autoSave(board1);
undostack.push(board1); // extra pushboard
clearInterval(clock);
startDate = new Date();
clock = setInterval(updateTime, 1000);
drawCanvas();
}
if (notLoaded) // readAsText is called before previous onload !
notLoaded = false;
else {
var file = event.target.files[0];
fileReader.readAsText(file);
}
}
function info() {
window.open("https://www.webtech4all.nl/SudokuHelp.htm");
}
window.onload = function(event) {
document.getElementById('importfile').addEventListener('change', onImport, false);
}
function clearUndo() {
undostack.clear();
}
function numericKeys() {
var context = canvas2.getContext('2d');
var SourceSize = BoardSize;
var row = 0;
var margin = 2;
for (var col = 0; col < SourceSize; col++) {
context.beginPath();
context.rect(col * digCellSize + margin + 0.5, row * digCellSize + margin + 0.5, digCellSize - 2 * margin, digCellSize - 2 * margin);
context.fillStyle = "#ffffe0";
context.fill();
}
context.font = "24pt Calibri";
context.textAlign = "center";
context.textBaseline = "middle";
var normalForeColor = "#708090";
context.fillStyle = normalForeColor; // text color - dark
for (var col = 0; col < SourceSize; col++) {
var x = (col + 0.5) * digCellSize; // center of cell for textAlign center, textBaseline middle
var y = 0.5 * digCellSize;
var value = col + 1;
context.fillStyle = normalForeColor;
context.fillText(value, x, y);
}
}
function colorKeys() {
var context = canvas2.getContext('2d');
var SourceSize = BoardSize;
var row = 0;
var margin = 2;
for (var col = 0; col < SourceSize; col++) {
context.beginPath();
context.rect(col * digCellSize + margin + 0.5, row * digCellSize + margin + 0.5, digCellSize - 2 * margin, digCellSize - 2 * margin);
context.fillStyle = colors[col];
context.fill();
}
}
// App starts here
if (typeof(Storage) == "undefined") {
board1.clear();
board1.setString("1......454..7......57...38.8..59.4....6.2.5....9.73..8.15...86......8..797......4"); // CTC hidden triple + XY-wing
board1.initCandidates();
}
else {
var str = localStorage.getItem("sudoku");
var vers = localStorage.getItem("version");
if (str === null || str === "") {
board1.clear();
board1.setString("1......454..7......57...38.8..59.4....6.2.5....9.73..8.15...86......8..797......4"); // CTC hidden triple + XY-wing
board1.initCandidates();
startDate = new Date();
}
else if (vers === null || vers != version) {
board1.clear();
board1.setString("1......454..7......57...38.8..59.4....6.2.5....9.73..8.15...86......8..797......4"); // CTC hidden triple + XY-wing
board1.initCandidates();
startDate = new Date();
}
else {
obj = JSON.parse(str);
board1.copyFrom(obj);
var time = localStorage.getItem("time");
if (time === null)
time = "0";
elapsedTime = parseInt(time);
startDate = new Date();
startDate.setTime(startDate.getTime() - elapsedTime);
}
}
undostack.push(board1); // extra pushboard for undo
drawCanvas();
var digCellSize = 60;
// Digit selector in second canvas
function initDigitSource() {
// Only ever called once!
var context = canvas2.getContext('2d');
context.strokeStyle = '#808080';
var SourceSize = BoardSize;
for (var i = 0; i <= SourceSize; i++) {
context.beginPath();
// Draw vertical lines
context.lineWidth = 1;
context.moveTo(i * digCellSize + 0.5, 0.5);
context.lineTo(i * digCellSize + 0.5, SourceSize * digCellSize + 0.5);
context.stroke();
}
for (var i = 0; i <= 1; i++) {
context.beginPath();
// Draw horizontal lines
context.lineWidth = 1;
context.moveTo(0.5, i * digCellSize + 0.5);
context.lineTo(SourceSize * digCellSize + 0.5, i * digCellSize + 0.5);
context.stroke();
}
numericKeys();
normal();
}
initDigitSource();
canvas2.onclick = function canvasMouseClick(ev) {
var time = new Date().getTime();
var coords = this.relMouseCoords(ev);
var dig = Math.floor(coords.x / digCellSize) + 1;
if (dig == 10)
dig = 0;
if (time - prevTime < 500) {
// assume double click, note that you don't have something like dblTap for touchscreens
if (mode < 3) {
undostack.undo(board1);
markCells(dig);
}
else if (mode == 4) {
undostack.undo(board1);
clearColors(dig);
}
}
else {
if (mode < 4) {
var prevMode = mode;
if (mode == 2 && event.shiftKey)
mode = 1;
if (mode == 3 && event.ctrlKey)
mode = 1;
setDigitInCell(dig);
mode = prevMode;
}
else
setColorInCell(dig);
}
prevTime = time;
}
function updateTime(){
var endDate = new Date();
elapsedTime = endDate - startDate;
var s = Math.floor(elapsedTime / 1000);
var m = 0;
var h = 0;
if (s > 59) {
m = Math.floor(s / 60);
s = Math.floor(s % 60);
if (m > 59) {
h = Math.floor(m / 60);
m = Math.floor(m % 60);
}
}
h = h % 10;
h = "" + h;
if (m < 10)
m = "0" + m;
if (s < 10)
s = "0" + s;
var time = h + ":" + m + ":" + s;
document.getElementById("clock").innerText = time;
}
function autoSave(obj) {
if (typeof(Storage) !== "undefined") {
var str = JSON.stringify(obj);
localStorage.setItem("sudoku", str);
localStorage.setItem("version", version);
localStorage.setItem("time", "" + elapsedTime);
}
}
</script>
</div>
</div>
</body>
</html>
]]>
