UVa 10667

　　题目大意：这个也是和UVa 836 - Largest Submatrix差不多，修改一下数据就可以套用代码的。

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define MAXN 110

int mat[MAXN][MAXN], sum[MAXN][MAXN];

int main()
{
#ifdef LOCAL
    freopen("in", "r", stdin);
#endif
    int T;
    scanf("%d", &T);
    while (T--)
    {
        int n, k;
        scanf("%d%d", &n, &k);
        int r1, c1, r2, c2;
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                mat[i][j] = 1;
        while (k--)
        {
            scanf("%d%d%d%d", &r1, &c1, &r2, &c2);
            for (int i = r1; i <= r2; i++)
                for (int j = c1; j <= c2; j++)
                    mat[i][j] = -20000;
        }
        memset(sum, 0, sizeof(sum));
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                sum[i][j] = mat[i][j] + sum[i-1][j] + sum[i][j-1] - sum[i-1][j-1]; 
        int ans = 0;
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                for (int p = i; p <= n; p++)
                    for (int q = j; q <= n; q++)
                    {
                        int t = sum[p][q] - sum[p][j-1] - sum[i-1][q] + sum[i-1][j-1];
                        ans = max(ans, t);
                    }
        printf("%d
", ans);
    }
    return 0;
}