样例对了，全是WA求助

#include<bits/stdc++.h>
#include<iostream>
using namespace std;
typedef long long ll;
long long n, m, a[1145][1145], c, s[1145][1145], ans, ansi, ansj;
int main(){
    cin >> n >> m >> c;
    for ( long long int i = 1; i <= n; i ++ )
	{
        for ( long long int j = 1; j <= m; j ++ )
		{
            cin >> a[i][j];
            s[i][j] = s[i - 1][j] + s[i][j - 1] - s[i - 1][j - 1] + a[i][j];
        }
    }
    for ( long long int i = 1; i <= n; i ++ )
	{
        for ( long long int j = 1; j <= m; j ++ )
		{ 
            long long sum = s[i + c - 1][j + c - 1] + s[i - 1][j - 1] - s[i - 1][j + c - 1] - s[i + c - 1][j - 1];
            if ( sum > ans )
			{
				ans = sum, ansi = i, ansj = j;
			}
        }
    }
    cout << ansi << ' ' << ansj << endl;
    return 0;
}

ying……