The New Sudoku Players' Forum

[Hajime]

Being home bound and not interested in 1000 piece jigsaw puzzles?, I present a 40 Sudoku Gattai: a giant Xmas bauble.
It has 10 Asterisk and 7 Girandola's and 1 Explosion. The inner and outer rings are connected by the green explosion Sudoku.
This puzzle is classified "easy", because It is solvable with "singles only". But with 2066 empty cells this is a huge project.



On the website are larges pictures, also with pencil marks https://sites.google.com/site/sisesuso/examples/xmas-bauble

The code for Pencil & Paper solvers is:

Hidden Text: Show

Code: Select all

#40//AC4/AI4/AF10,G/Z22/AL22/T28,A/AR28,A/N40/AX40/AF46,G/H52,A/Z52/AL52/BD52,A/E64/W64,A/AR64,A/BG64/B76,G/Q76,A/AC76,G/AU76/BJ76,G/E88/W88/AR88/BG88/H100,A/Z100/AL100/BD100,A/AF106,A/N112/AX112/T124/AR124/Z130,G/AL130,G/AF136/O40,N-5
.3..8.....91........6..1...........7....................3.........81....1...3....
.....345.............46......7...3......36..1......9.5.......4.....7..2.......7..
.....7..........36..................81.....7..3...................6..........5...
...........3..7........2...........8...3...........4....1..3.2......58......2...7
......3......91......4....824..75............8....6......71..6.9...54............
..........5.......132..9...32...7..1...9.........5......6.438.........6..........
...39.......6...............6...42.1.....2.......6......4..1.........9...28......
9....1..6..6.......1..2............1....3.6....1..8342..............6..7...9.....
...14....9...5..3.......657.......9.7....25.1.924........6..9.5....8....8........
4....9.........4..6.28........9..8..8..2.3.....7............................6....
..5.3.....6.........9..8....8.1...4....5....2......3................79....3.9....
.........27.56.8...4...8..7..........3.......6...7........8...3....1...2.........
8..91.2........................4...........85......9..3..48.....5...7.......36...
9.5.4................6.1...............3......97...8.......8...1...........2.....
..1.......9......7.....3.9..3....7.6........9...5.7................9...3.........
.......8........1...............76.4.............2..7....4.........7.9...........
......8.3........2.....4.....1.....46...9.....4....51...3.................8......
..8.............7.2..........3429...7.9.....1.2........5........6................
..........2.....9...1........27..5.43...4.........5.............68........5......
..18................5......3..1..............5..4......3............7.......1...6
.....1...9..............7.5...3......2.6..87.....17.4.......5...............8....
...........................9.3....78......49.....7.2.1........2...............1..
......4.2........6........14....9......3...6..95....3...............7............
...............4.........1.4.7.........39.........6.43.5.2.....1............3....
..............7.....6...........3...6..4.12..38.....4..6......9...........1....8.
.........75....................478..86...2............4.....9................873.
.68..............75........1.2...8...4......6................9.......21........74
2..............4...3.....2...6.2.......7.....49........5...1....7..36........2...
.....9.........92.....8..............2.......3....2......43.....54..7............
......4............28.5........98....7................4.......1...2...3....3..8..
............................1.........8.2.......3.7................6...8....1....
.....8......1...7......9......29.4.............................81.7............36
......8.....76...............8...4...9...8...31.......8....2...5..39.............
5.........37..5......9........89.4............68..3...............5...9.....3.7.6
.....7.......5............5...6......59..4.6.2...1...9.....9....8.7......7...89..
...92.......47........35....................5..............8..44......7....1.....
......2...6.........9..................79.6..9...4.......6.3.....72..........59..
............7.8....4................9...1.4.............6....21....3........26..8
...4.....6....59.......6........2..6.........9.........6....2.1.....85.3...25..9.
.................................................................................


The grids are sorted in reading order.

Here is also a much more difficult one, with the same layout; for Bit & Bytes solvers:

Hidden Text: Show

Code: Select all

#40//AC4/AI4/AF10,G/Z22/AL22/T28,A/AR28,A/N40/AX40/AF46,G/H52,A/Z52/AL52/BD52,A/E64/W64,A/AR64,A/BG64/B76,G/Q76,A/AC76,G/AU76/BJ76,G/E88/W88/AR88/BG88/H100,A/Z100/AL100/BD100,A/AF106,A/N112/AX112/T124/AR124/Z130,G/AL130,G/AF136/O40,N-5
....3....6....5......2......23........5..3..............1......2..6.......6......
...7..8.....48...3...6...........5........................3............6.....67..
...........3......................3.6................6..13..................9....
........1..27.5.....3.............1.6.......9....69......97.......3..7........5..
...1...7......3..9......25..............9.7.......2.3..1...8........7...8..3.....
............2..6..1...4......6........3...................9...2.....496......6...
.....7..57.........3....18.................9......3.7...8...........8..165.......
.........3.9..6....1........8....5.6...9.4.7......1..3...5........2..1......98...
.....29....1...5........6...1.5.........2..54.2..74.....5..3........7.......6....
.........95..6......1....46.....9...5..1......1.........7...................5....
.4.31.........2........4....36......8..1..........3.8...9.....8...6..........86..
..4..9...2.....5.........1.........7..328........7...............................
...7...........53......6.2.............9........2....4.....1........9...7..6.....
......6.....7..1.................463.........8.....9..3..9.......4...............
.7...9....4....6..........85.....3..1....7......2.......5....6.7......9.........3
...........8.......9.........2..9..1.......6....35.......5.7....2................
.......................9.......9..28..5..4..3....8..............................7
9.......................6.......7.....2....7..89...5.18.1......2.................
.1...5......7......5..........96....6.....3...4...7............8.................
.7.8.5...31..6..2..2.7.......8......4.62........6.................5..........9.6.
...7.1.4..............2.9..3...6........3.2...1...5.........4......7.............
......4.........5......7...1.....3.....7.3..9...85..........8....5.....3.......4.
..........................7.....2......4.5.7.76..1.5.................3.9..4......
........7...............5...8.7.....2....8......3158..51...............3...9.....
.....7......6......6..29........4...8..1.....5...9...6.3..................6......
..............5...6............3...28......9......1.3....57..........9......9....
.......................4..............83.59..4.37....5.......9................126
..............3...9.....2..1...4............9..35.......9.7.......9.1...21.......
..........................2....7......6.......3...2.......34.......5......41.....
...........7.2........5......4..7.......9.........2.................5817.......93
4............................9...8.....6..4..5....................5........1.....
........4.............6.......4........9.........8..............15....3...8......
....67.......................83.6...........42.58.........2......9.8........3....
..7..........2.......9.1.....3...867.....9.2..6.........9..31.....4....9.......4.
...1..........94.6...83........6....9.2......5..2...6...87.....1..............5..
...65...9.....2...............9.....1.......5.............1...2...2........8..7..
...5...8.......7...6......2..................5............9........6.........4...
...5........9..1..............4........3.........5....3.......4...............9..
.....2......4........5.1.......2.3......64.............8.....343....78.......6...
.................................................................................

Edit: url's with images redirected to dropbox

[creint]

Singles only and "easy" is a bit misleading on larger puzzles.
As a manual solver I avoid looking for naked singles. Having multiple small bottlenecks of requiring to find a locked single will make a puzzle very hard (unless you find more difficult logic that can make a shortcut).
It is very difficult to find 2 required locked singles out of 1600+ free cells or you can fall back to naked singles/sets but that is also hard without pencil marks.

Take for example this very very easy puzzle, it has a very large bottleneck so if you miss something it does not matter because you can find something else.

Hidden Text: Show

Code: Select all

2 . 6 . 3 . . 4 .
. . 5 . . 9 1 . 6
. 4 9 7 8 . . . 5
5 . . 4 . . 7 9 8
. 1 2 . . . . . .
. . . 5 6 . . . .
. . . . . 1 . . .
3 2 . . 9 . . 5 4
9 8 7 . . . . 2 .

Difficulty rating should be based on bottleneck size+difficulty compared to free cells, constraint rarity. Also direct unlocked singles (after locked singles) is easier than the need to keep pencil marks for your exclusion.
Bottleneck difficulty can only be based to the target user. Only need a formula from a mathematician to calculate this.

[Hajime]

Singles only and "easy" is a bit misleading on larger puzzles.
It is very difficult to find 2 required locked singles out of 1600+ free cells or you can fall back to naked singles/sets but that is also hard without pencil marks.
...
Difficulty rating should be based on bottleneck size+difficulty compared to free cells, constraint rarity.

I fully agree with you. Maybe a good intention for 2021 to extend/expand SE (Sukaku/Sudoku-rating) with size/labour of the puzzle.
SE is pretty established for single Sudoku's. Embracing SER and extending with Labour-rating (LAR) is wise.

SE rates with max(involved methods), so a swordfish-puzzle is rated the same as a swordfish-puzzle with 4 extra x-wings.
And a Samurai of 5 Sudokus with lots of free cells is more labour than max(max(involved methods per grid)).
Labour for solving the Xmas bauble puzzle

with 2066 empty cells this is a huge project