['1020', '2010', '0240', '0000']
6, 3, 2, 1, 5, 8, 7, 4, 9 4, 9, 5, 2, 7, 6, 8, 3, 1 8, 7, 1, 4, 3, 9, 5, 6, 2 5, 1, 7, 8, 4, 2, 3, 9, 6 3, 4, 6, 5, 9, 7, 2, 1, 8 2, 8, 9, 3, 6, 1, 4, 5, 7 1, 5, 8, 6, 2, 4, 9, 7, 3 7, 6, 4, 9, 8, 3, 1, 2, 5 9, 2, 3, 7, 1, 5, 6, 8, 4
1020201002400000
This is the only format which can store and retrieve lists of candidate values for the cells, as well as the known values. It will usually be easier to enter the values into the application, and use the program to write out a file. But data files can be written by hand if desired.
In the example below, the following points are worth noting:
<?xml version="1.0" ?> <sudoku> <size cols="4" rows="4"/> <cell col="1" row="1" value="1"/> <cell col="2" row="1" value="0"> <candidate value="2"/> <candidate value="3"/> </cell> <cell col="3" row="1" value="0"> <candidate value="3"/> </cell> <cell col="4" row="1" value="4"/> <cell col="1" row="2" value="0"> <candidate value="3"/> </cell> <cell col="2" row="2" value="0"> <candidate value="3"/> <candidate value="4"/> </cell> <cell col="3" row="2" value="0"> <candidate value="1"/> <candidate value="3"/> </cell> <cell col="4" row="2" value="2"/> <cell col="1" row="3" value="0"> <candidate value="2"/> <candidate value="3"/> </cell> <cell col="2" row="3" value="1"/> <cell col="3" row="3" value="0"> <candidate value="2"/> <candidate value="3"/> <candidate value="4"/> </cell> <cell col="4" row="3" value="0"> <candidate value="3"/> </cell> <cell col="1" row="4" value="4"/> <cell col="2" row="4" value="0"> <candidate value="2"/> <candidate value="3"/> </cell> <cell col="3" row="4" value="0"> <candidate value="1"/> <candidate value="2"/> <candidate value="3"/> </cell> <cell col="4" row="4" value="0"> <candidate value="1"/> <candidate value="3"/> </cell> </sudoku>