Cod sursa(job #718526)

Utilizator andu04Popa Andi andu04 Data 20 martie 2012 21:08:19
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.54 kb
#include <iostream>
#include <cstdio>
using namespace std;

int a[100001],n,m,val,poz;
int op,st,dr;
void update(int pozitie,int valoare)
{
    int k=0;
    while (pozitie<=n)
    {
        a[pozitie]+=valoare;
        while (!(pozitie & (1<<k))) k++;
        pozitie+= 1<<k;
        k++;
    }
}
int interval(int pozitie)
{
    int suma=0,k=0;
    while(pozitie)
    {
        suma+=a[pozitie];
        while(!(pozitie & (1<<k))) k++;
        pozitie-= 1<<k;
        k++;
    }
    return suma;
}
int cauta(int valoare)
{
    int N=1,k=0;
    while (N<n)
        N<<=1;
    while (N)
    {
        if (k+N<=n)
        {
            if (valoare>=a[k+N])
            {
                valoare-=a[k+N];
                if (!valoare)
                    return k+N;
            }
        }
        k=0;
        N>>=1;
    }
    return -1;
}

void citire()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++)
    {
        scanf("%d",&val);
        update(i,val);
    }
    for (int i=1;i<=m;i++)
    {
        scanf("%d",&op);
        if (op==0)
        {
            scanf("%d%d",&poz,&val);
            update(poz,val);
        }
        if (op==1)
        {
            scanf("%d%d",&st,&dr);
            printf("%d\n",interval(dr)-interval(st-1));
        }
        if (op==2)
        {
            scanf("%d",&val);
            printf("%d\n",cauta(val));
        }
    }
}

int main()
{
    citire();
    return 0;
}