Acwing 798.差分矩阵（模板）
题目
#include <iostream>
using namespace std;
const int N = 1010;
int n, m, q;
int a[N][N], b[N][N];
void insert(int x1, int y1, int x2, int y2, int c)
{
b[x1][y1] += c;
b[x2 + 1][y1] -= c;
b[x1][y2 + 1] -= c;
b[x2 + 1][y2 + 1] += c;
}
int main()
{
cin >> n >> m >> q;
for(int i = 1; i <= n; i ++ )
for(int j = 1; j <= m; j ++ ){
cin >> a[i][j];
insert(i, j, i, j, a[i][j]);
}
while(q -- ){
int x1, y1, x2, y2, c;
cin >> x1 >> y1 >> x2 >> y2 >> c;
insert(x1, y1, x2, y2, c);
}
for(int i = 1; i <= n; i ++ )
for(int j = 1; j <= m; j ++ )
b[i][j] += b[i - 1][j] + b[i][j - 1] - b[i - 1][j - 1];
for(int i = 1; i <= n; i ++ ){
for(int j = 1; j <= m; j ++ )
cout << b[i][j] << " ";
cout << endl;
}
return 0;
}