【HDOJ】1760 A New Tetris Game

博弈，主要是求SG值。终于做出点儿感觉。

/* 1760 */
#include <cstdio>
#include <cstring>
#include <cstdlib>

#define MAXN 55

char map[MAXN][MAXN];
int n, m;

int cal_SG() {
    int i, j, k, r, p;
    
    for (i=0; i<n-1; ++i) {
        for (j=0; j<m-1; ++j) {
            if (map[i][j]=='0' && map[i][j+1]=='0' && map[i+1][j]=='0' && map[i+1][j+1]=='0') {
                map[i][j] = map[i][j+1] = map[i+1][j] = map[i+1][j+1] = '1';
                k = cal_SG();
                map[i][j] = map[i][j+1] = map[i+1][j] = map[i+1][j+1] = '0';
                if (k == 0)
                    return 1;
            }
        }
    }
    return 0;
}

int main() {
    int i, j, k;
    
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
    #endif
    
    while (scanf("%d %d", &n, &m) != EOF) {
        for (i=0; i<n; ++i)
            scanf("%s", map[i]);
        if (cal_SG() == 0)
            puts("No");
        else
            puts("Yes");
    }
    
    return 0;
}