线段树

区间修改，区间查询

#include 
using namespace std;
#define LL long long
const int N = 1e5 + 10;
LL n, m, w[N], l, r, k, op;
struct node{
	LL l, r, sum, add;
}tr[N * 4];
void pushup(LL u){
	tr[u].sum = tr[u << 1].sum + tr[u << 1 | 1].sum;
}
void pushdown(LL u){
	auto &root = tr[u], &left = tr[u << 1], &right = tr[u << 1 | 1];
	if (root.add){
		left.add += root.add, left.sum += (left.r - left.l + 1) * root.add;
		right.add += root.add, right.sum += (right.r - right.l + 1) * root.add;
		root.add = 0;
	}
}
void build(LL u, LL l, LL r){
	if (l == r) tr[u] = {l, r, w[r], 0};
	else {
	    tr[u] = {l, r};
		LL mid = l + r >> 1;
		build(u << 1, l, mid);
		build(u << 1 | 1, mid + 1, r);
		pushup(u);
	}
}
void update(LL u, LL l, LL r, LL k){
	if (tr[u].l >= l && tr[u].r <= r){
		tr[u].sum += (LL) (tr[u].r - tr[u].l + 1) * k;
		tr[u].add += k;
	}
	else {
		pushdown(u);
		LL mid = tr[u].l + tr[u].r >> 1;
		if (l <= mid) update(u << 1, l, r, k);
		if (r > mid) update(u << 1 | 1, l, r, k);
		pushup(u);
	}
}
LL query(LL u, LL l, LL r){
	if (tr[u].l >= l && tr[u].r <= r) return tr[u].sum;
	pushdown(u);
	LL mid = tr[u].l + tr[u].r >> 1, sum = 0;
	if (l <= mid) sum = query(u << 1, l, r);
	if (r > mid) sum += query(u << 1 | 1, l, r);
	return sum;
}
int main(){
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
		scanf("%lld", &w[i]);
	build(1, 1, n);
	while (m--){
		cin >> op;
		if (op == 1){
			scanf("%lld%lld%lld", &l, &r, &k);
			update(1, l, r, k);
		}
		else {
			scanf("%lld%lld", &l, &r);
			cout << query(1, l, r) << "\n";
		}
	}
	return 0;
}

洛谷模板：https://www.luogu.com.cn/problem/P3372
Acwing模板：https://www.acwing.com/problem/content/244/