洛谷是不是不能起这种引流性标题来着（
by s1mp1ng @ 2024-05-19 21:44:58
@[s1mp1ng](/user/1093247) 好像是
by chenshixue @ 2024-07-02 09:27:13
```
void add(int x, int y, int s) {
for (int i = x; i <= n; i += lowbit(i)) {
for (int j = y; j <= m; j += lowbit(j)) {
t[0][i][j] += s;
t[1][i][j] += s * i;
t[2][i][j] += s * j;
t[3][i][j] += s * i * j;
}
}
}
```
把这一段代码改成
```
void add(int x, int y, int s) {
for (int i = x; i <= n; i += lowbit(i)) {
for (int j = y; j <= m; j += lowbit(j)) {
t[0][i][j] += s;
t[1][i][j] += x * i;
t[2][i][j] += y * j;
t[3][i][j] += s * x * y;
}
}
}
```
by YCN_AK_NOI @ 2024-07-20 14:53:50
@[UnforgettableDream](/user/1347770) 建议直接用标准的输入输出，自己写快读很容易出问题
by YCN_AK_NOI @ 2024-07-20 15:00:11
数组空间开到2050就可以了 @[UnforgettableDream](/user/1347770)
by YCN_AK_NOI @ 2024-07-20 15:01:28
@[UnforgettableDream](/user/1347770) 建议养成良好的代码风格
by YCN_AK_NOI @ 2024-07-20 15:07:21
@[YCN_AK_NOI](/user/965461) qwq，谢谢，不过我早 AC 了，不好意思，而且确实是小写 k （
by UnforgettableDream @ 2024-07-20 15:09:16