树状数组【模板】

https://www.luogu.com.cn/problem/P3374

#include<bits/stdc++.h>
using namespace std;
#define endl '\n'
#define lowbit(x)  x&(-x)
using ll = long long;
using pii = pair<int, int>;
const double PI = acos(-1);
const int N = 5e5 + 10;
const int mod = 1e9 + 7;
ll a[N];
int n,m;
void add_dandian(int x,int k){
	for(int i=x;i<=n;i+=lowbit(i)){
		a[i]+=k;
	}
}
ll query(int l,int r){//查询[l,r]的和
	ll ans=0;
	for(int i=r;i;i-=lowbit(i)){
		ans+=a[i];
	}
	for(int i=l-1;i;i-=lowbit(i)){
		ans-=a[i];
	}
	return ans;
}
void solve() {
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		int x;cin>>x;
		add_dandian(i,x);
	}
		
	while(m--){
		int t,x,y;cin>>t>>x>>y;
		if(t==1){
			add_dandian(x,y);
//			for(int i=1;i<=n;i++)
//				cout<<a[i]<<" ";
//			cout<<endl;
		}
		else{
			cout<<query(x,y)<<endl;
		}
	}
}

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