Cod sursa(job #2139280)

Utilizator radurotaruRotaru Radu Stefan radurotaru Data 22 februarie 2018 12:47:18
Problema Statistici de ordine Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include <fstream>
#include <cstdlib>

using namespace std;
ifstream f("sdo.in");
ofstream g("sdo.out");
int v[3000001],k,n;
void swap(int *a,int *b)
{
    int t=*a;
    *a=*b;
    *b=t;
}
int partition(int v[],int q,int w)
{
    int x=v[w];
    int i=q;
    for(int j=q; j<=w-1; j++)
    {
        if(v[j]<=x)
        {
            swap(v[i],v[j]);
            i++;
        }
    }
    swap(v[i],v[w]);
    return i;
}
void randompartition(int v[],int q,int w)
{
    if(q<w)
    {
        int n=w-q+1;
        int pivot=rand()%n;
        swap(v[q+pivot],v[w]);
        int r=partition(v,q,w);
        if(r!=k)
        {
        randompartition(v,q,r-1);
        randompartition(v,r+1,w);
        }
    }

}
int main()
{
    f>>n>>k;
    for(int i=1; i<=n; i++)
        f>>v[i];
    randompartition(v,1,n);
    g<<v[k];
    return 0;
}