diff options
Diffstat (limited to 'modules/benchmark/nqueens.c')
-rw-r--r-- | modules/benchmark/nqueens.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/modules/benchmark/nqueens.c b/modules/benchmark/nqueens.c new file mode 100644 index 00000000..838731c4 --- /dev/null +++ b/modules/benchmark/nqueens.c @@ -0,0 +1,37 @@ +/* + * N-Queens Problem Solver + * Found somewhere on the Internet; can't remember where. Possibly Wikipedia. + */ +#include <stdio.h> +#include <stdbool.h> +#include <stdlib.h> + +#define QUEENS 11 + +int row[QUEENS]; + +bool safe(int x, int y) +{ + int i; + for (i = 1; i <= y; i++) + if (row[y - i] == x || row[y - i] == x - i || row[y - i] == x + i) + return false; + return true; +} + +int nqueens(int y) +{ + int x; + + for (x = 0; x < QUEENS; x++) { + if (safe((row[y - 1] = x), y - 1)) { + if (y < QUEENS) { + nqueens(y + 1); + } else { + break; + } + } + } + + return 0; +} |