Cod sursa(job #1674841)

Utilizator robertkarolRobert Szarvas robertkarol Data 4 aprilie 2016 21:39:17
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n,m,i,a,b,x,arb[100001],t;
void update(int ind, int val)
{
    int poz=0;
    while(ind<=n)
    {
        arb[ind]+=val;
        while((ind&(1<<poz))==0) poz++;
        ind+=(1<<poz); poz++;
    }
}
int query(int ind)
{
    int poz=0,s=0;
    while(ind>0)
    {
        s+=arb[ind];
        while((ind&(1<<poz))==0) poz++;
        ind-=(1<<poz); poz++;
    }
    return s;
}
int search(int val)
{
    int pas=1,i=0;
    while(pas<n) pas*=2;
    while(pas)
    {
        if(i+pas<=n)
            if(val>=arb[i+pas])
        {
            val-=arb[i+pas];
            i+=pas;
            if(val==0) return i;
        }
        pas/=2;
    }
    return -1;
}
int main()
{
    fin>>n>>m;
    for(i=1;i<=n;i++)
    {
        fin>>x;
        update(i,x);
    }
    for(i=1;i<=m;i++)
    {
        fin>>t;
        if(t==0)
        {
            fin>>a>>b;
            update(a,b);
        }
        else if(t==1)
        {
            fin>>a>>b;
            fout<<query(b)-query(a-1)<<"\n";
        }
        else
        {
            fin>>a;
            fout<<search(a)<<"\n";
        }
    }
    return 0;
}