BNU 1440-board Problem

 

Question address: http://acm.bnu.edu.cn/bnuoj/problem_show.php? PID = 1, 1440

 

Similar to Queen N, direct DFS enumeration.

 

# Include <stdio. h> # include <string. h> char map [8] [9]; int res; int y [8], HS [64]; void DFS (int I, int N, int m) {If (! M) {res ++; return ;}for (; I <n; I ++) for (Int J = 0; j <n; j ++) if (! Y [J]) if (Map [I] [J] = '#') {Y [J] = 1; DFS (I + 1, n m-1 ); Y [J] = 0 ;}} int main () {int I, n, m; while (~ Scanf ("% d", & N, & M), N> 0) {for (I = 0; I <n; I ++) scanf ("% s", map [I]); memset (Y, 0, sizeof (y); Res = 0; // Why does DFS not use TLE, kids shoes who have done the eight queens problem should know that such questions are similar to a full arrangement // but now the size of this question is only 8*8, that is, a maximum of O (8 !) Complexity of DFS (0, n, m); printf ("% d \ n", Res);} return 0 ;}