sudoku
Sudoku, also known as Number Place, is a logic-based placement puzzle. The aim of the puzzle is to enter a digit from 1 through 9 in each cell of a 9×9 grid made up of 3×3 subgrids (called "regions"), starting with various digits given in some cells. See the picture below (the regions are delimited by thick lines).
Each row, column, and region must contain only one instance of each digit. Completing
the puzzle requires patience and logical ability. Although first published in
a U. S. puzzle magazine in 1979, Sudoku initially caught on in Japan in 1986
and attained international popularity in 2005.
Task
Write a program that solves the sudoku puzzle.
Input
data
Input file sudoku.in
contains 9 lines, each line containing
a sequence of 9 digits, corresponding
to the rows of the board. Blank cells are denoted by zeros.
Output data
Output file
sudoku.out will contain 9
lines, each line containing 9
nonzero distinct digits, representing the solution of the puzzle. The digits
written on the same line will not be separated by spaces.
Constraints
Each test puzzle has a unique
solution.
Example
sudoku.in | sudoku.out |
530070000 600195000 098000060 800060003 400803001 700020006 060000280 000419005 000080079 |
534678912
672195348 198342567 859761423 426853791 713924856 961537284 287419635 345286179 |
Time limit: 0.15 seconds
Prof. DSc
Stoyan Kapralov
Technical University - Gabrovo, Bulgaria
Contact: s.kapralov@gmail.com