Cod sursa(job #1095187)

Utilizator alex_ovidiunituAlex Ovidiu Nitu alex_ovidiunitu Data 30 ianuarie 2014 15:53:51
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <fstream>
using namespace std;
int a[100014],n,m;
inline int zero (int x)
{
    return (x^(x-1))&x;
}
void update (int poz, int nr)
{
    int i;
    for (i=poz;i<=n;i+=zero(i))
        a[i]+=nr;
}
int query (int poz)
{
    int i,s=0;
    for (i=poz;i>0;i-=zero(i))
        s+=a[i];
    return s;
}
int search (int val)
{
    int st=1,dr=n,mij;
    while (st<=dr)
    {
        mij=(st+dr)/2;
        if (query(mij)==val)
            return mij;
        if (query(mij)<val)
            st=mij+1;
        else
            dr=mij-1;
    }
    return -1;
}
int main()
{
    int i,j,nr,poz,aa,b,k;
    fstream f,g;
    f.open("aib.in",ios::in);
    g.open("aib.out",ios::out);
    f>>n>>m;
    for (i=1;i<=n;i++)
    {
        f>>nr;
        poz=i;
        update(poz,nr);
    }
    for (i=1;i<=m;i++)
    {
        f>>cod;
        if (cod==0){
            f>>poz>>nr;
            update(poz,nr);
        }
        if (cod==1){
            f>>aa>>b;
            g<<query(b)-query(aa-1)<<'\n';
        }
        if (cod==2){
            f>>k;
            g<<search(k)<<'\n';
        }
    }
}