uva 108(最大连续矩阵和)

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
const int N = 105;
const int INF = -0x3f3f3f3f;

int main() {
int n, s

, sum

, x, y, maxx;
while (scanf("%d", &n) != EOF) {
maxx = INF;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
scanf("%d", &s[i][j]);
for (int i = 0; i < n; i++)
sum[i][0] = sum[0][i] = 0;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
sum[i][j] = sum[i][j - 1] + sum[i - 1][j] - sum[i - 1][j - 1] + s[i][j];//减掉重复的
for (int i = 1; i <= n; i++)
for (int j = i; j <= n; j++)
for (int p = 1; p <= n; p++)
for (int q = p; q <= n; q++) {
int temp = sum[j][q] - sum[j][p - 1] - sum[i - 1][q] + sum[i - 1][p - 1];//加上多减的
if (temp > maxx)
maxx = temp;
}
printf("%d\n", maxx);
}
return 0;
}