The New Sudoku Players' Forum

[AR4793]

Is there a know puzzle which only used hidden singles to solve?

How about a puzzle only using naked singles?

Thanks,
Herb

[ronk]

Is there a know puzzle which only used hidden singles to solve?

How about a puzzle only using naked singles?

Courtesy of the Patterns Game, here are six puzzles that can be solved with only hidden singles ...

Code: Select all

1..2..3...2..1..4...3..5..67..6..5...5..8..7...8..4..18..7..4...3..6..2...9..2..7
..1...2.....3.4...5...6...1.5.1.2.7...8...4...2.9.7.8.9...7...8...5.9.....3...7..
1...2...3.4.....1...5.4.6.....2.1...7.8...1.5...4.8.....7.6.8...8.....2.4...3...7
1...2...3.4.....5....6.7.....5...8..7...8...2..6...9.....8.2....1.....6.2...7...1
1..2..3......4..5...6..7..82.....7...5..1..4...7.....98..1..2...6..2......4..6..7
...........12.34...235.617..35...74.....3.....76...82..143.825...87.23...........

and six solvable with only naked singles.

Code: Select all

..........1.2.3.4....456....47...89...2.7.6...98...75....684....3.7.1.6..........
..4...9...37...54.19.....38...1.3......589......2.4...46.....89.12...36...5...7..
1.2...3.......4.5.5.6.2...7...1...4...5...8...3...6...7...9.1.8.8.3.......4...9.6
......1......2..34..3.5.67..1...2..8..4.6.5..3..1...2..95.4.8..68..1......2......
......9......2..36..8.9.47..7...2..1..4.6.7..6..3...2..92.4.8..38..1......7......
..9.8.7...6...5.4.3.....5.2.......3.6...7.4...8.......2.7.1...3.4.7...9...5...8..

[AR4793]

ronk,

Thanks!

I've been trying to decide which is the more primitive between naked singles and hidden singles. It has to be naked singles.

As your puzzles show, puzzles can be created which can be solved only by invoking a rule operating on naked singles.

However it is impossible to create a puzzle that can only be solved with hidden singles. LOL when I figured it out. Think of the last cell to be filled. It has to be a naked single.

Thanks again,
Herb

[ronk]

However it is impossible to create a puzzle that can only be solved with hidden singles. LOL when I figured it out. Think of the last cell to be filled. It has to be a naked single.

When there is only one unfilled cell in a unit (row, column or box), it is simultaneously a naked and hidden single.

[Pat]

in the now-lost discussion on
difficulty evaluation of sudokus with only hidden singles { t=14605 }
i had posted --

.5....63.9..1........4......32.8.......6..1........4..7...32.8.1.....9...........
18 clues
by gfroyle/gsf
-- solves in 19 steps of "hidden singles"
others then posted even more extreme results
which unfortunately i didn't save---