POJ_1050_最大子矩阵

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int a[105][105],temp[105];

int main()
{
    int n,ans = 0;
    scanf("%d",&n);
    for(int i = 1;i <= n;i++)
    {
        for(int j = 1;j <= n;j++)   scanf("%d",&a[i][j]);
    }
    for(int i = 1;i <= n;i++)
    {
        memset(temp,0,sizeof(temp));
        for(int j = i;j <= n;j++)
        {
            int sum = 0;
            for(int k = 1;k <= n;k++)
            {
                temp[k] += a[j][k];
                sum += temp[k];
                ans = max(sum,ans);
                if(sum < 0) sum = 0;
            }
        }
    }
    printf("%d",ans);
    return 0;
}