简单线段树

#include <bits/stdc++.h>
using namespace std;
using ull = unsigned long long;
using ll  = long long;
const int N = 50010;
int T;
struct node {int l, r;ll sum, add;
} tr[N * 4];
ll a[N];
inline int ls(int p) {return p << 1;}
inline int rs(int p) {return p << 1 | 1;}
void pushup(int u) {tr[u].sum = tr[ls(u)].sum + tr[rs(u)].sum;
}
void pushdown(int u) {auto &left = tr[ls(u)], &right = tr[rs(u)], &root = tr[u];if (root.add) {left.add += root.add; left.sum += (ll)(left.r - left.l + 1) * root.add;right.add += root.add; right.sum += (ll)(right.r - right.l + 1) * root.add;root.add = 0;}
}void build(int u, int l, int r) {if (l == r) tr[u] = {l, r, a[l], 0}; //(ll)?else {tr[u] = {l, r};int mid = l + r >> 1;build(ls(u), l, mid);build(rs(u), mid + 1, r);pushup(u);}
}void modi(int u, int l, int r, int v) {if (l <= tr[u].l && r >= tr[u].r) {tr[u].sum += (ll)(tr[u].r - tr[u].l + 1) * v;tr[u].add += v;} else {pushdown(u);int mid = tr[u].l + tr[u].r >> 1;if (l <= mid) modi(ls(u), l, r, v);if (r > mid) modi(rs(u), l, r, v);pushup(u);}
}ll query(int u, int l, int r) {if (l <= tr[u].l && r >= tr[u].r) return tr[u].sum;pushdown(u);ll v = 0;int mid = tr[u].l + tr[u].r >> 1;if (l <= mid) v = query(ls(u), l, r);if (r > mid) v += query(rs(u), l, r);return v;
}
int main() {ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);cin >> T;for (int cs = 1; cs <= T; cs ++) {memset(a, 0, sizeof(a));memset(tr, 0, sizeof(tr));int n;cin >> n;for (int i = 1; i <= n; i ++) cin >> a[i];build(1, 1, n);string op;cout << "Case " << cs << ":\n";while (cin >> op && op != "End") {if (op == "Add"){ll x, y;cin >> x >> y;modi(1, x, x, y);} else if (op == "Sub") {ll x, y;cin >> x >> y;modi(1, x, x, -y);} else if (op == "Query") {int x, y;cin >> x >> y;cout << query(1, x, y) << '\n';}} }return 0;
}