Odd-even diagonal sudoku

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Odd-even diagonal sudoku

Postby urhegyi » Wed Feb 10, 2021 11:04 am

Image
rules:
Image
solution:
Hidden Text: Show
Code: Select all
538279146962541738471683259296415873347896521185732964754968312619327485823154697
urhegyi
 
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Re: Odd-even diagonal sudoku

Postby urhegyi » Thu Feb 11, 2021 3:28 pm

I saw this was related to Gurths symmetrical placement!
The only conclusion I can make is that R4C6,R5C5,R6C4 must be odd!
Then it unfolds with a skyscraper and a naked quad!
So these are the only valid placements of Odd and Even candidates on the Diagonal!
Image
So R8C2 =1 and R2C8=3!
Quad 1579 box 3!
Quad 3579 box 7!
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Re: Odd-even diagonal sudoku

Postby 1to9only » Tue Sep 28, 2021 7:05 pm

This is an old thread, but I'm using this puzzle (amongst a few) for testing with SukakuExplainer!
Code: Select all
.3.........2......4..6.........1..7.3.7...5.1.8..3.........8..2......4.........9. ED=7.8/7.8/2.6

Solution Path: Show
Code: Select all
2.6, Pointing: Cells R8C1,R9C1: 8 in block and column: r1c1<>8, r2c1<>8
2.8, Claiming: Cells R5C4,R5C5,R5C6: 9 in row and block: r4c4<>9, r4c6<>9, r6c4<>9, r6c6<>9
2.8, Claiming: Cells R4C4,R5C5,R6C6: 2 in antidiagonal(\) and block: r5c4<>2, r4c6<>2, r6c4<>2, r5c6<>2
2.8, Claiming: Cells R4C4,R5C5,R6C6: 4 in antidiagonal(\) and block: r5c4<>4, r4c6<>4, r6c4<>4, r5c6<>4
2.8, Claiming: Cells R7C7,R8C8,R9C9: 3 in antidiagonal(\) and block: r7c8<>3, r8c9<>3, r9c7<>3
2.9, Generalized Intersection: Cells R3C3,R3C5,R3C7: 8 in row: r5c5<>8
2.6, Pointing: Cells R4C4,R5C4: 8 in block and column: r2c4<>8, r1c4<>8
7.6, Nishio Forcing Chain (w/6 nodes): R2C8.4 on ==> R9C2.4 both on & off: r2c8<>4
7.6, Nishio Forcing Chain (w/6 nodes): R8C2.2 on ==> R5C8.2 both on & off: r8c2<>2
7.8, Nishio Forcing Chain (w/9 nodes): R1C9.8 on ==> R4C7.8 both on & off: r1c9<>8
7.8, Nishio Forcing Chain (w/10 nodes): R3C7.8 on ==> R4C4.8 both on & off: r3c7<>8
6.6, Turbot Fish (w/4 nodes): R5C8.8 off: r5c8<>8
1.5, Hidden Single: R5C4: 8 in row 5: r5c4=8
2.0, Direct Hidden Pair: Cells R4C7,R4C9: 3,8 in block: r4c9<>4,6,9, r4c7<>2,6,9, r6c7=9
1.5, Hidden Single: R3C7: 2 in column 7: r3c7=2
2.8, Claiming: Cells R7C7,R9C7: 6 in column and block: r7c8<>6, r8c9<>6, r8c8<>6, r9c9<>6
2.9, Generalized Intersection: Cells R7C3,R7C5,R7C7: 6 in row: r5c5<>6
2.6, Pointing: Cells R4C6,R5C6,R6C6: 6 in block and column: r8c6<>6, r9c6<>6
7.1, Forcing Chain (w/6 nodes): R1C6.4 off: r1c6<>4
7.1, Forcing Chain (w/6 nodes): R2C6.4 off: r2c6<>4
6.6, Turbot Fish (w/4 nodes): R5C5.4 off: r5c5<>4
2.0, Direct Hidden Pair: Cells R4C4,R6C6: 2,4 in block: r4c4<>5, r6c6<>5,6,7, r6c4=7
1.2, Hidden Single: R4C6: 5 in block 5: r4c6=5
1.2, Hidden Single: R5C6: 6 in block 5: r5c6=6
1.2, Hidden Single: R5C5: 9 in block 5: r5c5=9
2.6, Pointing: Cells R6C8,R6C9: 6 in block and row: r6c1<>6, r6c3<>6
3.0, Naked Pair: Cells R1C4,R4C4: 2,4 in column: r7c4<>4, r2c4<>4, r8c4<>2, r9c4<>2,4
3.0, Naked Pair: Cells R6C6,R9C6: 2,4 in column: r8c6<>2, r1c6<>2
3.0, Naked Pair: Cells R1C9,R6C9: 4,6 in column: r2c9<>4,6
1.5, Hidden Single: R2C5: 4 in row 2: r2c5=4
1.2, Hidden Single: R9C6: 4 in block 8: r9c6=4
1.2, Hidden Single: R4C4: 4 in block 5: r4c4=4
1.0, Hidden Single: R6C6: 2 in block 5: r6c6=2
1.2, Hidden Single: R5C8: 2 in block 6: r5c8=2
1.0, Hidden Single: R5C2: 4 in row 5: r5c2=4
1.2, Hidden Single: R7C3: 4 in block 7: r7c3=4
1.2, Hidden Single: R1C8: 4 in block 3: r1c8=4
1.2, Hidden Single: R6C9: 4 in block 6: r6c9=4
1.2, Hidden Single: R6C8: 6 in block 6: r6c8=6
1.2, Hidden Single: R1C9: 6 in block 3: r1c9=6
1.5, Hidden Single: R4C3: 6 in column 3: r4c3=6
1.2, Hidden Single: R4C2: 9 in block 4: r4c2=9
1.2, Hidden Single: R4C1: 2 in block 4: r4c1=2
1.2, Hidden Single: R9C2: 2 in block 7: r9c2=2
1.2, Hidden Single: R8C1: 6 in block 7: r8c1=6
1.2, Hidden Single: R2C2: 6 in block 1: r2c2=6
1.2, Hidden Single: R9C1: 8 in block 7: r9c1=8
1.2, Hidden Single: R2C9: 8 in block 3: r2c9=8
1.2, Hidden Single: R3C9: 9 in block 3: r3c9=9
1.2, Hidden Single: R3C8: 5 in block 3: r3c8=5
1.2, Hidden Single: R4C7: 8 in block 6: r4c7=8
1.0, Hidden Single: R4C9: 3 in block 6: r4c9=3
1.2, Hidden Single: R8C5: 2 in block 8: r8c5=2
1.2, Hidden Single: R1C4: 2 in block 2: r1c4=2
1.2, Hidden Single: R9C7: 6 in block 9: r9c7=6
1.2, Hidden Single: R7C5: 6 in block 8: r7c5=6
1.2, Hidden Single: R8C8: 8 in block 9: r8c8=8
1.2, Hidden Single: R1C3: 8 in block 1: r1c3=8
1.2, Hidden Single: R2C1: 9 in block 1: r2c1=9
1.2, Hidden Single: R1C1: 5 in block 1: r1c1=5
1.2, Hidden Single: R3C2: 7 in block 1: r3c2=7
1.0, Hidden Single: R3C3: 1 in block 1: r3c3=1
1.2, Hidden Single: R2C4: 5 in block 2: r2c4=5
1.2, Hidden Single: R3C5: 8 in block 2: r3c5=8
1.0, Hidden Single: R3C6: 3 in row 3: r3c6=3
1.2, Hidden Single: R1C6: 9 in block 2: r1c6=9
1.2, Hidden Single: R2C6: 1 in block 2: r2c6=1
1.0, Hidden Single: R1C5: 7 in block 2: r1c5=7
1.0, Hidden Single: R9C5: 5 in column 5: r9c5=5
1.0, Hidden Single: R8C6: 7 in column 6: r8c6=7
1.0, Hidden Single: R1C7: 1 in row 1: r1c7=1
1.2, Hidden Single: R2C7: 7 in block 3: r2c7=7
1.0, Hidden Single: R2C8: 3 in block 3: r2c8=3
1.0, Hidden Single: R7C7: 3 in column 7: r7c7=3
1.0, Hidden Single: R7C8: 1 in column 8: r7c8=1
1.2, Hidden Single: R6C1: 1 in block 4: r6c1=1
1.0, Hidden Single: R6C3: 5 in block 4: r6c3=5
1.0, Hidden Single: R7C1: 7 in column 1: r7c1=7
1.2, Hidden Single: R8C2: 1 in block 7: r8c2=1
1.0, Hidden Single: R7C2: 5 in column 2: r7c2=5
1.0, Hidden Single: R7C4: 9 in row 7: r7c4=9
1.2, Hidden Single: R8C3: 9 in block 7: r8c3=9
1.0, Hidden Single: R9C3: 3 in block 7: r9c3=3
1.2, Hidden Single: R9C4: 1 in block 8: r9c4=1
1.0, Hidden Single: R8C4: 3 in block 8: r8c4=3
1.0, Hidden Single: R8C9: 5 in row 8: r8c9=5
1.0, Hidden Single: R9C9: 7 in block 9: r9c9=7
ED=7.8/7.8/2.6
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