Sudoku

All formats · Reader spec · Cases and output

sudoku.iris reads a # size=N box=WxH header followed by an N×N grid. The alphabet 123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ0 maps to values 1–36; . maps to 0 for blank cells. Data contains n, box_width, box_height, and cells. Checks require the box area to equal N and every given value to be at most N; solving the puzzle and checking its uniqueness belong to the host.

The format source is the scaled sudoku corpus README. The reader spec is copied verbatim from Gecode’s sudoku-instances.hh.

• four-by-four uses a 4×4 grid with 2×2 boxes and blank cells.
• bad-box-size changes the box dimensions to 3×2. The reference reports E-CHECK-FAILED with an empty record path.

The instances statement permits several puzzles in one file; these samples each contain one. These are hand-made samples under the repository’s MIT license. See the library README for case layout, validation, and Gecode notices.

Reader spec

From Gecode commit 5e7bbd5c26b0702c6fd652356b2289da0710ac3c. Source notices.

sudoku.irisView full reader spec

format sudoku

instances {
  line "# size={n:1..} box={box_width:1..}x{box_height:1..}"
  cells[n][n]: alphabet "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ0" blank "."

  check box_width * box_height == n "boxes must tile the grid"
  check max(cells) <= n "a value is larger than the size of the grid"
}

Cases and output

Run the commands from the repository root. Successful reads show dzn, JSON, and a summary. Rejected inputs show the CLI's diagnostic and caret, with the stable error code beside it.

bad-box-size

Box dimensions do not tile the grid

InputView full input

# size=4 box=3x2
1..4
.41.
.14.
4..1

E-CHECK-FAILED

check failed: boxes must tile the grid

Read rejectedRun from the repository root.

$ iris read formats/sudoku/sudoku.iris formats/sudoku/cases/bad-box-size/input.txt --dzn

formats/sudoku/cases/bad-box-size/input.txt:5:5: check failed: boxes must tile the grid
     5 | 4..1
       |     ^
while reading: instance [1]
spec: formats/sudoku/sudoku.iris:7

Input rejected

View full diagnosticDownload error JSON

Download full case · Open in playground

four-by-four

Four-by-four grid with two-by-two boxes

InputView full input

# size=4 box=2x2
1..4
.41.
.14.
4..1

dzn

iris read formats/sudoku/sudoku.iris formats/sudoku/cases/four-by-four/input.txt --dzn

dznView full dzn

n = 4;
box_width = 2;
box_height = 2;
cells = [| 1, 0, 0, 4
  | 0, 4, 1, 0
  | 0, 1, 4, 0
  | 4, 0, 0, 1 |];

JSON

iris read formats/sudoku/sudoku.iris formats/sudoku/cases/four-by-four/input.txt --json

JSONView full json

{"iris":"0.1","entries":[{"name":"n","type":"int","depth":0,"value":4},{"name":"box_width","type":"int","depth":0,"value":2},{"name":"box_height","type":"int","depth":0,"value":2},{"name":"cells","type":"int","depth":2,"value":[[1,0,0,4],[0,4,1,0],[0,1,4,0],[4,0,0,1]]}]}

Summary

iris read formats/sudoku/sudoku.iris formats/sudoku/cases/four-by-four/input.txt --summary

SummaryView full summary

formats/sudoku/cases/four-by-four/input.txt [sudoku]
  n: int 4
  box_width: int 2
  box_height: int 2
  cells: int array 4 x 4

Download full case · Open in playground