Cod sursa(job #2019629)

Utilizator sabinandreiBocan Sabin Andrei sabinandrei Data 8 septembrie 2017 10:45:42
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <fstream>
#define ub(x) (x&(-x))

using namespace std;
int x,i,y,z,n,m,aib[1000003],st,dr,j,pozitie,k;
ifstream f("aib.in");
ofstream g("aib.out");
int suma(int pozitie)
{
    int s=0;
    for(j=pozitie;j>0;j-=ub(j))
    {
        s+=aib[j];
    }
    return s;
}
void update(int pozitie,int val)
{
    for(j=pozitie;j<=n;j+=ub(j))
                    aib[j]+=val;
}
int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
    {
        f>>x;
        update(i,x);
    }
    for(i=1;i<=m;i++)
    {
        f>>x;
        if(x==0)
        {
            f>>y>>z;
            update(y,z);
        }
        else if(x==1)
        {
            f>>y>>z;
            g<<suma(z)-suma(y-1)<<'\n';
        }
        else if(x==2)
        {
            f>>y;
            st=1;
            dr=n;
            pozitie=-1;
            while(st<=dr && pozitie==-1)
            {
                k=(st+dr)/2;
                if(suma(k)==y)pozitie=k;
                else if(suma(k)>y)dr=k-1;
                else st=k+1;
            }
            g<<pozitie<<'\n';
        }
    }
    return 0;
}