Cod sursa(job #1278726)

Utilizator VictoriaNevTascau Victoria VictoriaNev Data 29 noiembrie 2014 12:09:27
Problema Arbori indexati binar Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <fstream>
#define NMAX 100001
using namespace std;
int aib[NMAX], n, k, i, x, a, b, s;

void update (int poz,int val)
{
    for (; poz<=n; poz+=poz&(poz-1)^poz)
        aib[poz]+=val;
}

int query(int poz)
{
    int s=0;
    for(; poz; poz-=poz&(poz-1)^poz)
        s+=aib[poz];
        return s;
}


int bs(int s)
{
    int med,st=1,dr=n,last=-1;
    while (st<=dr)
    {
        med=(dr+st)>>1;
        if (query(med)<=s)
            last=med,st=med+1;
        else
          dr=med-1;
    }
    if (query(last)==s)
    return last;
    else
    return -1;
}

int main()
{
    ifstream cin ("aib.in");
    ofstream cout ("aib.out");
    cin>>n>>k;
    for(i=1; i<=n; i++)
    {
        cin>>x;
        update(i,x);
    }
    for(i=1; i<=k; i++)
    {
        cin>>x;
        if(x==0)
        {
            cin>>a>>b;
            update(a,b);
        }
        else if(x==1)
        {
            cin>>a>>b;
            cout<<query(b)-query(a-1)<<'\n';
        }
        else
        {
            cin>>s;
            cout<<bs(s)<<'\n';
        }
        }
        return 0;
    }