Segment Tree sum

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MOD 1000000007;

#define got cout<<"Yes\n"; return;
#define got0 cout<<"Yes\n"; return 0;

#define bhak cout<<"No\n"; return;
#define bhak0 cout<<"No\n"; return 0;

#define bas cout<<"\n";

ll constructTree(ll ts, ll te, ll si, vector<ll> &tree, vector<ll> &vec){
    if(ts==te){
        return tree[si] = vec[ts];
    }

    ll mid = ts + (te-ts)/2;

    return tree[si] = constructTree(ts, mid, 2*si+1, tree, vec)
                    +
                    constructTree(mid+1, te, 2*si+2, tree, vec);

}

ll getSum(ll ts, ll te, ll rs, ll re, ll si, vector<ll> &tree){
    if(ts>=rs && te<=re){
        return tree[si];
    }

    if(ts==te){
        return 0;
    }

    ll mid = ts + (te-ts)/2;

    return getSum(ts, mid, rs, re, 2*si+1, tree)
            +
            getSum(mid+1, te, rs, re, 2*si+2, tree);
}

void update(ll ts, ll te, ll tar, ll pre, ll val, ll si, vector<ll> &tree){
    if(tar>=ts && tar<=te){
        tree[si] += val;
        tree[si] -= pre;
    }
    else{
        return;
    }

    if(ts==te){
        return;
    }

    ll mid = ts + (te-ts)/2;

    update(ts, mid, tar, pre, val, 2*si+1, tree);
    update(mid+1, te, tar, pre, val, 2*si+2, tree);
}

int main() {
    ll n, m; cin>>n>>m;

    vector<ll> vec(n);
    for(ll i=0; i<n; ++i) cin>>vec[i];

    vector<ll> tree(4*n, 0);


    constructTree(0, n-1, 0, tree, vec);

    while(m--){
        ll a, b, c;
        cin>>a>>b>>c;

        if(a==1){
            update(0, n-1, b, vec[b], c, 0, tree);
            vec[b] = c;
        }
        else if(a==2){
            // getSum(ll ts, ll te, ll rs, ll re, ll si, vector<ll> &tree){
            ll sum = getSum(0, n-1, b, c-1, 0, tree);
            cout<<sum; bas
        }
    }

    return 0;
}