差分矩阵

#include <bits/stdc++.h>
using namespace std;
const int N = 1010;
int b[N][N];   //可以只存储一个差分矩阵

void insert(int x1,int y1,int x2,int y2,int c)  
{
    b[x1][y1] += c;      //右下角所有点全部加上c
    b[x1][y2 + 1] -= c;  
    b[x2 + 1][y1] -=c;
    b[x2 + 1][y2 + 1] +=c;   //重复减去的补上
}

int main()
{
    int n,m,q;
    scanf("%d%d%d",&n,&m,&q);
    for(int i = 1; i <= n; i ++)
    {    for(int j = 1; j <= m; j ++)
        {
            int a;
            scanf("%d",&a);
            insert(i,j,i,j,a);  //初始化差分矩阵
         }
    }
    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];    //前缀和 相当于a[i][j]
            printf("%d ",b[i][j]);
        }
        printf("\n");

    }
    return 0;
}