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author | Agney Lopes Roth Ferraz <agney@debian.org> | 2009-03-28 22:55:02 -0300 |
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committer | Simon Quigley <tsimonq2@ubuntu.com> | 2017-06-19 14:38:48 -0500 |
commit | 1b6665085f47e0a86e4bebd5e313a2ab63600eb4 (patch) | |
tree | 6b7dedc1886b42d07cc48359470fe3f595500cc8 /nqueens.c | |
parent | 819c0c3382b06fc0f0a1679465966f811aa2e0f8 (diff) | |
parent | 4979bb6cbbbe39eb44c32530cd13f86bf44e5d77 (diff) |
Import Debian changes 0.5c-1
hardinfo (0.5c-1) unstable; urgency=low
* New upstream version.
(Closes: #517591, #511237, #457703, #519256, #449250, #457820, #497758)
Diffstat (limited to 'nqueens.c')
-rw-r--r-- | nqueens.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/nqueens.c b/nqueens.c new file mode 100644 index 00000000..838731c4 --- /dev/null +++ b/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; +} |