poj 1321

来源：互联网发布：中国少数民族政策知乎编辑：程序博客网时间：2024/05/16 22:21

棋盘问题

深度优先搜索

#include <iostream>#include <sstream>#include <cstdio>#include <cstring>#include <cmath>#include <string>#include <vector>#include <set>#include <cctype>#include <algorithm>#include <cmath>#include <deque>#include <queue>#include <map>#include <queue>#include <list>#include <iomanip>using namespace std;                                               //////#define INF 0xffffff7#define N 10#define max(a,b)(a>b?a:b)///char board[N][N];int n, k;int cnt;int color[N][N];bool isok(int a, int b){int i, j;for (i = 1; i <= n; i++){if (color[i][b] == 1)return false;}for (i = 1; i <= n; i++){if (color[a][i] == 1)return false;}return true;}void dfs(int cur, int tot){int i, j;if (tot == k){cnt++;return;}if (cur > n )return;//在第cur行放置棋子for (j = 1; j <= n; j++){if (board[cur][j] == '#' && color[cur][j] == 0 && isok(cur, j)){color[cur][j] = 1;dfs(cur + 1, tot + 1);color[cur][j] = 0;}}//如果不放置棋子dfs(cur + 1, tot);}int main(){///int i, j;while (1){cin >> n >> k;if (n == -1 || k == -1)break;for (i = 1; i <= n; i++)for(j = 1; j <= n; j++)cin >> board[i][j];cnt = 0;if (k == 0){cout << 0 << endl;continue;}memset(color, 0, sizeof(color));dfs(1, 0);cout << cnt << endl;}///    return 0;}