【数据结构 二维树状数组】luogu_ 4514 上帝造题的七分钟

题意

维护矩阵区间和，区间修改操作。

思路

二维树状数组。
先挖坑，这里贴篇blog

代码

#include <cstdio>

int n, m, a, b, c, d, delta;
char op;
int t[4][2100][2100];

inline int lowbit(int x) {
	return x & -x;
}

void add(int x, int y, int val) {
	for (int i = x; i <= n; i += lowbit(i))
		for (int j = y; j <= m; j += lowbit(j)) {
			t[0][i][j] += val;
			t[1][i][j] += val * x;
			t[2][i][j] += val * y;
			t[3][i][j] += val * x * y;
		}
}

int query(int op, int x, int y) {
	int res = 0;
	for (int i = x; i >= 1; i -= lowbit(i))
		for (int j = y; j >= 1; j -= lowbit(j))
			res += t[op][i][j];
	return res;
}

int ask(int x, int y) {
	return query(0, x, y) * (x * y + x + y + 1) - query(1, x, y) * (y + 1) - query(2, x, y) * (x + 1) + query(3, x, y);
}

int main() {
	scanf("X %d %d", &n, &m);
	while (scanf("%s", &op) != EOF) {
		scanf("%d %d %d %d", &a, &b, &c, &d);
		if (op == 'L') {
			scanf("%d", &delta);
			add(a, b, delta);
			add(a, d + 1, -delta);
			add(c + 1, b, -delta);
			add(c + 1, d + 1, delta);
		} else printf("%d\n", ask(c, d) - ask(a - 1, d) - ask(c, b - 1) + ask(a - 1, b - 1));
	}
}