C++ 代码

#include <iostream>
#include <algorithm>
using namespace std;

const int N = 5010;
int n, m;
int s[N][N];

int main()
{
    int N, R;
    cin >> N >> R;
    n = m = 5001;
    while (N -- )
    {
        int x, y, w;
        cin >> x >> y >> w;
        x ++, y ++ ;
        s[x][y] += w;
    }

    for (int i = 1; i <= n; i ++ )
        for (int j = 1; j <= m; j ++ )
            s[i][j] += s[i - 1][j] + s[i][j - 1] - s[i - 1][j - 1];

    int res = 0;
    for (int i = R; i <= n; i ++ )
        for (int j = R; j <= m; j ++ )
            res = max(res, s[i][j] - s[i - R][j] - s[i][j - R] + s[i - R][j - R]);

    cout << res << endl;

    return 0;
}