Cod sursa(job #3243977)

Utilizator daria_diaconuDiaconu daria_diaconu Data 22 septembrie 2024 17:11:21
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.15 kb
#include <fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int a[10000002];
int n,m,cer,y;
void update(int i,int b)
{
    while(i<=n)
    {
        a[i]+=b;
        i+=i&(-i);
    }
}
int calc(int i)
{
    int sum=0;
    while(i>0)
    {
        sum+=a[i];
        i-=i&(-i);
    }
    return sum;
}
int cb(int b)
{
    int s=1,dr=n;
    while(s<=dr)
    {
        int mj=(s+dr)/2;
        if(calc(mj)<b)
            s=mj+1;
        else
            dr=mj-1;
    }
    return s;
}
int main()
{
    int x;
    fin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        fin>>x;
        update(i,x);
    }
    for(int i=0;i<m;i++)
    {
        fin>>cer;
        if(cer==0)
        {
            fin>>x>>y;
            update(x,y);
        }
        else if(cer==1)
        {
            fin>>x>>y;
            fout<<calc(y)-calc(x-1)<<'\n';
        }
        else
        {
            fin>>x;
            int r=cb(x);
            if(calc(r)==x)
            {
                fout<<r<<'\n';
            }
            else
                fout<<-1<<'\n';
        }

    }
    return 0;
}