nth_element

#include <fstream>
#include <algorithm>
#include <vector>
#define InFile "cioc.in"
#define OutFile "cioc.out"
using namespace std;
vector<int> a;

bool myfunction(int i,int j)
{
    return (i<j);
}

int main()
{
    int c,n,k,x;
    ifstream f(InFile);
    f>>c>>n>>k;
    for(int i=0;i<n;++i)
        f>>x,a.push_back(x);
    f.close();
    random_shuffle(a.begin(),a.end());
    nth_element(a.begin(),a.begin()+k,a.end(),myfunction);
    nth_element(a.begin(),a.begin()+k,a.end());
    ofstream g(OutFile);
    if(c==1)
    {
        g<<k;
    }
    else
    {
        for(vector<int> ::iterator it=a.begin();it!=a.end();++it)
            g<<*it<<' ';
        g<< '\n';
    }
    g.close();
    return 0;
}