Cod sursa(job #3225808)

Utilizator Mihai_AritonMihai Ariton Mihai_Ariton Data 18 aprilie 2024 23:08:21
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <bits/stdc++.h>
using namespace std;
 
int bit[150005];
int n;
void update(int p, int val)
{
    while(p<=n)
    {
        bit[p]+=val;
        p+=(p&(-p));
    }
}
int prefix(int p)
{
    int sum=0;
    while(p>0)
    {
        sum+=bit[p];
        p-=(p&(-p));
    }
    return sum;
}
int main()
{
    ifstream cin("aib.in");
    ofstream cout("aib.out");
    
    int q, tip, a, b, nr, st, dr, mij, ans;
    cin>>n>>q;
    for(int i=1; i<=n; i++)
    {
        cin>>a;
        update(i, a);
    }
    for(int i=1; i<=q; i++)
    {
        cin>>tip;
        if(tip==0)
        {
            cin>>a>>b;
            update(a, b);
        }
        else if(tip==1)
        {
            cin>>a>>b;
            nr=prefix(b)-prefix(a-1);
            cout<<nr<<'\n';
        }
        else
        {
            cin>>a;
            st=1;dr=n;ans=-1;
            while(st<=dr)
            {
                mij=(st+dr)/2;
                nr=prefix(mij);
                //cout<<mij<<" "<<nr<<'\n';
                if(nr<=a)
                {
                    ans=mij;
                    st=mij+1;
                }
                else
                dr=mij-1;
            }
            if(ans==-1)
            cout<<"-1\n";
            else
            {
                if(prefix(ans)==a)
                cout<<ans<<'\n';
                else
                cout<<"-1\n";
            }
        }
    }
 
    return 0;
}