题解 | #【模板】线段树1#

树状数组模板。

#include<bits/stdc++.h>
#define int long long
#define double long double
#define x first
#define y second
using namespace std;
typedef long long LL;
typedef long long ll;
typedef pair<int, int> PII;
const int N = 3e5 + 10;
const int M = 1e3 + 10;
int mod = 1e9 + 7;
ll n, tree[500001];
ll lowbit(ll num) {
    return num & -num;
}
void build(ll s, ll num) {
    for (ll i = s; i <= n; i += lowbit(i)) tree[i] += num;
}
ll ask(ll s) {
    ll ans = 0;
    for (ll i = s; i >= 1; i -= lowbit(i)) ans += tree[i];
    return ans;
}

void solve() {
    int q;
    cin >> n >> q;
    for (int i = 1; i <= n; i++) {
        int x;
        cin >> x;
        build(i, x);
    }
    while (q--) {
        int op, l, x;
        cin >> op >> l >> x;
        if (op == 1) {
            build(l, x);
        } else {
            cout << ask(x) - ask(l - 1) << "\n";
        }
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int _;
    _ = 1;
    //cin>>_;
    while (_--) {
        solve();
    }
}