UVa108

#include <stdio.h>
#include <string.h>

int a[110][110], dp[110][110];

int main(int argc, char *argv[])
{
    int n, i, j, k, g, max;
    while(scanf("%d", &n) != EOF)
    {
        for(i = 1; i <= n; i++)
            for(j = 1; j <= n; j++)
                scanf("%d", &a[i][j]);

        max = -10000000;
        memset(dp, 0, sizeof(dp));
        for(g = 1; g <= n; g++)
            for(k = 1; k <= n; k++)
            {
                for(i = g; i <= n; i++)
                    for(j = k; j <= n; j++)
                    {
                        dp[i][j] = dp[i - 1][j] + dp[i][j - 1] - dp[i - 1][j - 1] + a[i][j];
                        if(dp[i][j] > max)
                            max = dp[i][j];
                    }
                memset(dp, 0, sizeof(dp));
            }

        printf("%d\n", max);

    }
    return 0;
}