Cod sursa(job #3313454)

Utilizator SGLDCASA SI PODUL SGLD Data 4 octombrie 2025 16:54:22
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <fstream>
using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
int aib[100001],arr[100001];
int lsb(int r)
{
    return (r&(-r));
}
int n;
void update(int x,int y)
{
    for(int i=x; i<=n; i+=lsb(i))
    {
        aib[i]+=y;
    }
}
int sum(int a)
{
    int nr=0;
    for(int i=a; i>=1; i-=lsb(i))
    {
        nr+=aib[i];
    }
    return nr;
}
int main()
{
    int ans=0,m,nr1,nr2,nr3;
    cin>>n>>m;
    for(int i=1; i<=n; i++)
    {
        cin>>arr[i];
        update(i,arr[i]);
    }
    for(int i=1; i<=m; i++)
    {
        cin>>nr1>>nr2;
        if(nr1==0)
        {
            cin>>nr3;
            update(nr2,nr3);
        }
        else if(nr1==1)
        {
            cin>>nr3;
            cout<<sum(nr3)-sum(nr2-1)<<endl;
        }
        else
        {
            int poz=0,sumi=0;
            for(int d=17; d>=0; d--)
            {
                if(poz+(1<<d)<=n && sumi+aib[poz+(1<<d)]<nr2)
                {
                poz+=(1<<d);
                sumi+=aib[poz];
                }
            }
            if(poz+1>n || sum(poz+1)!=nr2){
            cout<<-1<<endl;
            }
            else{
            cout<<poz+1<<endl;
            }
        }
    }
    return 0;
}