SudoCue - File Formats

Introduction

As a courtesy to the people who want to write their own sudoku software, and those who like to learn more about the structure of sudoku files, this document describes the formats in the files created and recognized by SudoCue and SumoCue.

This documentation is up to date with version 1.4.1 of SudoCue. It was last updated on August 3, 2006.

We start with an overview of the file formats that this document explains.

.sdk

A file containing a single sudoku puzzle. The format is based on the Sadman file format, with a few additions to include additional information.

.sdm

A file containing a collection of sudoku puzzles. Each line contains a single puzzle.

.sdx

A file containing your work in progress. Proprietary to SudoCue. Contains a candidate grid and identifies user digits as opposed to given digits.

.scl

A file containing details about the rating and required solving techniques for a collection of puzzles. Proprietary to SudoCue.

.ss

Extension and format used by Simple Sudoku. SudoCue can read an write the files produced by this popular program.

Sudoku Puzzle (.sdk)

The file contains 9 lines, reach representing a row in the puzzle. Empty cells are represented by a dot. Additional information is optionally present in separate lines, starting with a hash character, followed by a single letter that identifies the type of info:

• A = Author
• D = Description
• C = Comment
• B = Date published
• S = Source (name of newspaper, book or website)
• L = Level
• U = Source URL

These additional lines are only recognized by SudoCue. Sadman sudoku also uses this format, but it does not recognize these entries.

An example:

#ARuud
#DA random puzzle created by SudoCue
#CJust start plugging in the numbers
#B03-08-2006
#SSudoCue
#LEasy
#Uhttp://www.sudocue.net/
2..1.5..3
.54...71.
.1.2.3.8.
6.28.73.4
.........
1.53.98.6
.2.7.1.6.
.81...24.
7..4.2..1

Sudoku Puzzle Progress (.sdx)

This format contains a line for each row in the grid. A blank separates the cells. For unsolved cells, the candidates are listed without separating space. Solved cells are preceded by u when they are placed by the user, the givens have no prefix.

2 679 6789 1 46789 5 469 9 3
389 5 4 69 689 68 7 1 29
9 1 679 2 4679 3 4569 8 59
6 9 2 8 u1 7 3 59 4
3489 3479 3789 56 2456 46 u1 2579 2579
1 47 5 3 24 9 8 27 6
3459 2 39 7 3589 1 59 6 589
359 8 1 569 3569 6 2 4 579
7 369 369 4 35689 2 59 359 1

Sudoku Puzzle Collection (.sdm)

This is a very simple format. Each line contains a single puzzle. The empty cells are represented by a zero, but the program also accepts other placeholders, like a dot “.”. Line breaks in Windows or Unix style are recognized, but when my software writes these files, CrLb is always used. These files cannot be written by SudoCue. The program can only read them.

016400000200009000400000062070230100100000003003087040960000005000800007000006820
049008605003007000000000030000400800060815020001009000010000000000600400804500390
760500000000060008000000403200400800080000030005001007809000000600010000000003041
000605000003020800045090270500000001062000540400000007098060450006040700000203000
409000705000010000006207800200000009003704200800000004002801500000060000905000406
000010030040070501002008006680000003000302000300000045200500800801040020090020000
080070030260050018000000400000602000390010086000709000004000800810040052050090070
000093006000800900020006100000080053006000200370050000002500040001009000700130000

Simple Sudoku (.ss)

In a simple sudoku file, the data is stored in a human readable format.

1..|...|7..
.2.|...|5..
6..|38.|...
-----------
.78|...|...
...|6.9|...
...|...|14.
-----------
...|.25|..9
..3|...|.6.
..4|...|..2

There is an older format for Simple Sudoku files, which you may still encounter:

X6X1X4X5X
XX83X56XX
2XXXXXXX1
8XX4X7XX6
XX6XXX3XX
7XX9X1XX4
5XXXXXXX2
XX72X69XX
X4X5X8X7X

Collection file analysis (.scl)

There is a menu option File/Classify that can be used to mass-rate puzzle collections. When you select it, there will be a save dialog that allows you to name the .scl file to which the ratings will be written. For large collections with many extremely difficult puzzles, rating a collection will take a long time.
Here is an example of what you may see in a collection file:

[SCLV120]
[C:\Sudokus\Collections\top95.sdm]
000001=R=67;B=0;S=842;FH=19;D1=7;M1=24;B1=2;R1=3;C1=4;US=3;N1=2;LP=2;LT=1
000002=R=67;B=0;S=846;FH=19;D1=7;M1=21;B1=2;R1=5;C1=4;US=3;N1=3;LP=2;LT=1
000003=R=67;B=0;S=830;FH=19;D1=7;M1=25;B1=2;R1=3;C1=3;US=3;N1=2;LP=2;LT=1
000004=R=86;B=0;S=3642;FH=19;D1=7;M1=23;B1=4;R1=1;C1=2;N1=8;LP=2;LT=1;L1=10;N2=1;H2=5;Y2=1;U1=1;TC=1
000005=R=77;B=0;S=1925;FH=17;D1=7;M1=24;B1=2;R1=2;US=2;N1=10;LT=2;L1=7;L2=1;N2=2;RP=1
000006=R=73;B=0;S=1422;FH=20;D1=7;M1=29;B1=5;C1=3;LP=1;L1=8

The first line identifies the SudoCue rating file version. The second line is the path of the file that was rated. There is a line for each puzzle in the collection, it stars with the sequence number, followed by entries in (key=value) format, separated by a semicolon. The following table explains the meaning of each key: