Cod sursa(job #3310828)

Utilizator Tudor_11Tudor Ioan Calin Tudor_11 Data 17 septembrie 2025 09:57:35
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.41 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int aib[100001];
void update(int node,int n,int val)
{
    while(node<=n)
    {
        aib[node]+=val;
        node+=(node &(-node));
    }
}
int query(int node)
{
    int ans=0;
    while(node)
    {
        ans+=aib[node];
        node-=(node & (-node));
    }
    return ans;
}
int main()
{
    int n,m,x,t,a,b;
    fin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        fin>>x;
        update(i,n,x);
    }
    for(int i=1;i<=m;i++)
    {
        fin>>t>>a;
        //cout<<t<<' ';
        if(t==0)
        {
            fin>>b;
            update(a,n,b);
        }
        else if(t==1)
        {
            fin>>b;
            fout<<query(b)-query(a-1)<<'\n';
        }
        else
        {
            int st=1,dr=n+1;
            bool ok=0;
            while(st<dr)
            {
                int mid=(st+dr)/2;
                int val=query(mid);
                if(val==a)
                {
                    ok=1;
                    fout<<mid<<'\n';
                    break;
                }
                else if(val>a)
                {
                    dr=mid;
                }
                else
                {
                    st=mid+1;
                }
            }
            if(!ok) fout<<"-1\n";
        }
    }
    return 0;
}