Solution for Hard Sudoku #4157841326918
4
3
6
9
2
5
7
8
1
2
9
7
8
1
3
4
5
6
5
1
8
6
7
4
9
2
3
1
9
3
8
6
7
5
4
2
7
4
2
5
3
1
9
6
8
8
6
5
4
9
2
7
3
1
3
5
9
2
7
4
6
1
8
6
2
4
1
8
9
3
7
5
1
8
7
3
5
6
2
4
9
This Sudoku Puzzle has 61 steps and it is solved using Hidden Single, Locked Triple, Naked Single, Locked Candidates Type 1 (Pointing), Naked Pair, undefined, Skyscraper, Full House techniques.
Naked Single
Explanation
Hidden Single
Explanation
Locked Candidates
Explanation
Full House
Explanation
Solution Steps:
- Row 8 / Column 2 → 7 (Hidden Single)
- Locked Triple: 4,7,8 in r456c7 => r3c7,r5c9<>4, r37c7,r46c8,r5c9<>8, r46c8<>7
- Row 5 / Column 9 → 2 (Naked Single)
- Row 5 / Column 3 → 7 (Naked Single)
- Locked Candidates Type 1 (Pointing): 3 in b4 => r7c3<>3
- Locked Candidates Type 1 (Pointing): 3 in b6 => r23c8<>3
- Locked Candidates Type 1 (Pointing): 6 in b6 => r8c8<>6
- Naked Pair: 4,8 in r5c17 => r5c46<>4, r5c6<>8
- X-Wing: 1 c37 r37 => r3c2458,r7c2568<>1
- Skyscraper: 1 in r8c5,r9c2 (connected by r2c25) => r9c46<>1
- Row 9 / Column 2 → 1 (Hidden Single)
- Row 3 / Column 3 → 1 (Hidden Single)
- Row 3 / Column 7 → 9 (Naked Single)
- Row 7 / Column 7 → 1 (Naked Single)
- Row 7 / Column 2 → 5 (Hidden Single)
- Row 7 / Column 8 → 8 (Naked Single)
- Row 3 / Column 8 → 2 (Naked Single)
- Row 8 / Column 8 → 5 (Naked Single)
- Row 8 / Column 9 → 6 (Naked Single)
- Row 9 / Column 9 → 9 (Full House)
- Row 8 / Column 1 → 2 (Naked Single)
- Row 7 / Column 3 → 9 (Naked Single)
- Row 8 / Column 4 → 1 (Naked Single)
- Row 8 / Column 5 → 8 (Full House)
- Row 4 / Column 3 → 3 (Naked Single)
- Row 6 / Column 3 → 2 (Full House)
- Row 7 / Column 1 → 3 (Naked Single)
- Row 9 / Column 1 → 6 (Full House)
- Row 5 / Column 4 → 5 (Naked Single)
- Row 4 / Column 8 → 6 (Naked Single)
- Row 7 / Column 6 → 4 (Naked Single)
- Row 7 / Column 5 → 2 (Full House)
- Row 5 / Column 6 → 1 (Naked Single)
- Row 9 / Column 4 → 3 (Naked Single)
- Row 9 / Column 6 → 5 (Full House)
- Row 4 / Column 5 → 4 (Naked Single)
- Row 6 / Column 8 → 3 (Naked Single)
- Row 1 / Column 6 → 7 (Naked Single)
- Row 3 / Column 4 → 4 (Naked Single)
- Row 2 / Column 5 → 1 (Naked Single)
- Row 3 / Column 5 → 5 (Naked Single)
- Row 6 / Column 5 → 6 (Full House)
- Row 4 / Column 4 → 7 (Naked Single)
- Row 6 / Column 6 → 8 (Full House)
- Row 2 / Column 6 → 3 (Full House)
- Row 1 / Column 4 → 2 (Full House)
- Row 1 / Column 8 → 1 (Naked Single)
- Row 2 / Column 8 → 7 (Full House)
- Row 3 / Column 2 → 8 (Naked Single)
- Row 3 / Column 9 → 3 (Full House)
- Row 4 / Column 7 → 8 (Naked Single)
- Row 4 / Column 2 → 9 (Full House)
- Row 6 / Column 2 → 4 (Naked Single)
- Row 2 / Column 2 → 2 (Full House)
- Row 5 / Column 1 → 8 (Full House)
- Row 5 / Column 7 → 4 (Full House)
- Row 6 / Column 7 → 7 (Full House)
- Row 2 / Column 9 → 4 (Naked Single)
- Row 1 / Column 9 → 8 (Full House)
- Row 1 / Column 1 → 4 (Full House)
- Row 2 / Column 1 → 9 (Full House)
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