代码如下：
#include <bits/stdc++.h>
using namespace std;
int c[5005][4005];
int main() {
int n,m;
cin >> n >> m;
int maxi= 0,maxj = 0;
for (int i=1;i<=n;++i) {
int x,y,z;
cin >> x >> y >> z;
c[x][y] = z;
maxi = max(x,maxi);
maxj = max(y,maxj);
}
++maxi;
++maxj;
for (int i=0;i<maxi;++i) {
for (int j=0;j<maxj;++j) c[i][j] = c[i - 1][j] + c[i][j - 1] + c[i][j] - c[i - 1][j - 1];
}
int maxs = -2147483647;
for (int i=0;i<maxi-m;++i) {
for (int j=0;j<maxj-m;++j) {
int x = i,y = j,x2 = x + m - 1,y2 = y + m - 1;
maxs = max(maxs, c[x2][y2] - c[x - 1][y2] - c[x2][y - 1] + c[x - 1][y - 1]);
}
}
cout << maxs;
return 0;
}
调了必关！！！
