【HDOJ】1510 White Rectangles

这个题目很好，变形的题目也很多。简单DP。

/* 1510 */
#include <cstdio>
#include <cstring>
#include <cstdlib>

#define MAXN 105

char map[MAXN][MAXN];
int dp[MAXN][MAXN];

int min(int a, int b) {
    return a<b ? a:b;
}

int main() {
    int n;
    int i, j, k, tmp;
    int sum;
    
    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
    #endif
    
    while (scanf("%d", &n) != EOF) {
        for (i=1; i<=n; ++i)
            scanf("%s", map[i]+1);
        
        sum = 0;
        for (i=1; i<=n; ++i) {
            for (j=1; j<=n; ++j) {
                if (map[i][j] == '#') {
                    dp[i][j] = 0;
                } else {
                    dp[i][j] = dp[i-1][j] + 1;
                    tmp = dp[i][j];
                    sum += tmp;
                    for (k=j-1; k>0; --k) {
                        tmp = min(tmp, dp[i][k]);
                        sum += tmp;
                    }
                }
            }
        }
        printf("%d
", sum);
    }
    
    return 0;
}