ZOJ 1636 Evaluate Matrix Sum

#include <cstdio>
#include <cstring>
using namespace std;
#define N 505
int s

, n, m, l
;

int main() {
int T;
scanf("%d", &T);
for (int cas=1; cas<=T; cas++) {
printf("Case %d:\n", cas);
scanf("%d%d", &n, &m);
memset(s, 0, sizeof(s));
memset(l, 0, sizeof(l));

int a;
for (int i=1; i<=n; i++)
for (int j=1; j<=m; j++) {
scanf("%d", &a);
l[j] += a*a;
s[i][j] = s[i][j-1] + l[j];
}
int r1, r2, c1, c2;
scanf("%d", &a);
while (a--) {
scanf("%d%d%d%d", &r1, &c1, &r2, &c2);
printf("%d\n", s[r2][c2]-s[r2][c1-1]-s[r1-1][c2]+s[r1-1][c1-1]);
}
}
return 0;
}