[AcWing 798] 差分矩阵

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#include<iostream>

using namespace std;
const int N = 1e3 + 10;
int a[N][N], b[N][N];
void insert(int x1, int y1, int x2, int y2, int c)
{
    b[x1][y1] += c;
    b[x1][y2 + 1] -= c;
    b[x2 + 1][y1] -= c;
    b[x2 + 1][y2 + 1] += c;
}
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 ++)
            scanf("%d", &a[i][j]);
    for (int i = 1; i <= n; i ++)
        for (int j = 1; j <= m; j ++)
            insert(i, j, i, j, a[i][j]);
    while (q --) {
        int x1, y1, x2, y2, c;
        scanf("%d %d %d %d %d", &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 ++)
            printf("%d ", b[i][j]);
        printf("\n");
    }
    return 0;
}

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1. 注意插入函数的操作；
2. 矩阵求前缀和；