解决#8WA的很赖皮的逃课方法（#8原理求解）

#include <bits/stdc++.h>
using namespace std;
int price[5140][5140] = {0};
int lsum[5140][5140]  = {0};
int n,m;
int x,y,v;
int manx = -1,many = -1;
int main()
{
    cin >> n >> m;
    while(n--)
    {
        cin >> x >> y >> v;
        price[x+1][y+1] += v;
        manx = max(x+1,manx); 
        many = max(y+1,many);
    }
    for(int i = 1; i <= max(manx,many); i++)
    {//                     ^改了此处，原为manx^
        for(int j = 1; j <= max(manx,many); j++)
        {
            lsum[i][j] = price[i][j] + lsum[i-1][j] + lsum[i][j-1] - lsum[i-1][j-1];
        }
    }
    int manv = -1;
    for(    int i = 1; i <= manx/*x+1*/; i++)
    {
        for(int j = 1; j <= many; j++)
        {
            manv = max(manv,lsum[i-1+m][j-1+m] - lsum[i-1][j-1+m] - lsum[i-1+m][j-1] + lsum[i-1][j-1]);
        }
    }
    cout << manv;
}