SudokuSolver Forum

All sudoku puzzles in this forum post are the intellectual property of Børge Alexander Tetlie Anderssen.
Copyright © 2009 Børge Alexander Tetlie Anderssen.  All rights reserved.  Terms of Use.

There are three difficulties to choose from.
All three puzzles have the same solution.

The difficulty levels explained     The ratings explained

A) Novice.
B) Apprentice (mainstream edition).
C) Master (27 Intersection, 4 Naked Pair, 1 Naked Triplet, 2 Uniqueness Test 1: one on {35} in g4 and one on {25} in g5). Select to view details.
The advanced techniques are needed in 2 different grids.



Regular Samurai #81A (Novice)

Rating based on required solving techniques:  Moderate

000000510107004000040096002008060020010009000004071800080000000306008000000020000
000079000000000070040000503000000310006004000001008050000000009000200080000040001
000026000000000000000030000050000702000080090690700000000000000000003000000090000
000004000720000000006900000160000000007801020000050390000046030004035006002000000
000000000000005004000302080000009000098000010000410600060000000502000006001060709



Regular Samurai #81B (Apprentice)

Rating based on required solving techniques:  Tough

000000510107004000040096002008060020010009000004071800080000000306008000000020000
000079000010000070040000503000000310006004000001008050000000009000200080000040001
000026000000000000000030000050000002000080090690700000000000000000053000000090000
000004000720000000006900000160000000007801020000050390000046000004035006002000000
000000000000005004000302080000009000098000010003410600060200000502000006001060709



Regular Samurai #81C (Master)

Rating based on required solving techniques:  Extra Hard

000000510107004000040096002008060020010009000004071800000000000306008000000020000
000079000000000070040000503000000310006004000001008050000000009000200080000040001
000026000000000000000030000050000702000080090690700000000000000000053000000090000
000004000720000000006900000160000000007801020000050390000046030004035006002000000
000000000000005004000302080000000000098000010003410600060000000502000006001060709

_________________
Quis custodiet ipsos custodes?

Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]

Thanks for this Master version Børge. I thought I'd found a new move in step 1 but I see your solver found it. Looks like I don't quite understand that technique fully yet. At least it's valid!


Regular Samurai #81C (Master) Walkthrough

Cheers
Ed

Ed,

Thanks for another WT.

The Uniqueness Test is valid because there is no A or B in r1 in n3.

Any occurrence of A or B in r2 in n3 would make the puzzle invalid, i.e. it would have no solution.
Any occurrence of A in r2 in n3 -> two cells in r2 having B as the only possibility. Same reasoning for any occurrence of B in r2 in n3.

_________________
Quis custodiet ipsos custodes?

Normal: [D  Y-m-d,  G:i]     PM->email: [D, d M Y H:i:s]