Cod sursa(job #1863638)

Utilizator SagunistuStrimbu Alexandru Sagunistu Data 31 ianuarie 2017 04:24:04
Problema Statistici de ordine Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#include <algorithm>
#include <cstdlib>

using namespace std;

int n,sct,a[3000005],b[3000005],c[3000005],vfb,vfc;

ifstream fin("sdo.in");
ofstream fout("sdo.out");

void read()
{
    fin>>n>>sct;
    for(int i=0;i<n;i++)
        fin>>a[i];
}

int part(int a[],int p,int q,int r)
{
    swap(a[r],a[q-1]);
    r=q-1;
    int i=p-1,x=a[r];
    for(int j=p;j<q-1;j++)
        if(a[j]<=x)
        {
            i++;
            swap(a[i],a[j]);
        }
    swap(a[i+1],a[r]);
    return i+1;
}

int select(int a[],int p,int q,int k)
{
    int r=rand()%(q-p)+p;
    r=part(a,p,q,r);
    int k1=r;
    if(k==k1)
        return a[k];
    else
    if(k<k1)
        return select(a,p,k1,k);
    else
        return select(a,k1+1,q,k);
}

int main()
{
    read();
    //fout<<part(a,0,n,a[0])<<"\n";
    fout<<select(a,0,n,sct-1);
   // fout<<nth_element()
    return 0;
}