一、思路
二、代码
#include <cstdio>
#include <cstring>
typedef long long ll;
const int maxn = 1e5 +5;
int t, n, q, code, x, y;
ll sum[maxn << 2], lazy[maxn << 2], add;
void pushdown(int id, int l, int r) {
if (lazy[id] == 0) return;
int mid = (l + r) >> 1;
lazy[id << 1] += lazy[id];
lazy[id << 1 | 1] += lazy[id];
sum[id << 1] += lazy[id] * (mid - l + 1);
sum[id << 1 | 1] += lazy[id] * (r - mid);
lazy[id] = 0;
}
void update(int id, int l, int r, int x, int y, ll add) {
if (x <= l && r <= y) {
sum[id] += (r - l + 1) * add;
lazy[id] += add;
return;
}
pushdown(id, l, r);
int mid = (l + r) >> 1;
if (x <= mid) update(id << 1, l, mid, x, y, add);
if (y > mid) update(id << 1 | 1, mid + 1, r, x, y, add);
sum[id] = sum[id << 1] + sum[id << 1 | 1];
}
ll query(int id, int l, int r, int x, int y) {
if (x <= l && r <= y) {
return sum[id];
}
pushdown(id, l, r);
int mid = (l + r) >> 1;
ll ans = 0;
if (x <= mid) ans += query(id << 1, l, mid, x, y);
if (y > mid) ans += query(id << 1 | 1, mid + 1, r, x, y);
return ans;
}
int main() {
scanf("%d", &t);
for (int cas = 1; cas <= t; cas++) {
memset(sum, 0, sizeof(sum));
memset(lazy, 0, sizeof(lazy));
scanf("%d%d", &n, &q);
for (int i = 1; i <= q; i++) {
scanf("%d", &code);
if (code == 0) {
scanf("%d%d%lld", &x, &y, &add);
update(1, 1, n, x, y, add);
} else {
scanf("%d%d", &x, &y);
printf("%lld\n", query(1, 1, n, x, y));
}
}
}
return 0;
}
