Cod sursa(job #1970828)

Utilizator caprariuapCaprariu Alin-Paul caprariuap Data 19 aprilie 2017 17:19:42
Problema Statistici de ordine Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <stack>
#include <iomanip>
#include <queue>
#include <cstdlib>
#include <ctime>
using namespace std;

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

#define nmax 1000010
int a[nmax],n,i,k;

int divide(int p, int q)
{
    int st,dr,x;
    x=rand()%(q-p+1)+p;
    swap(a[x],a[p]);
    x=a[p];
    st=p;
    dr=q;
    while (st<dr)
    {
        while (st<dr&&a[dr]>=x)
            dr--;
        a[st]=a[dr];
        while (st<dr&&a[st]<=x)
            st++;
        a[dr]=a[st];
    }
    a[st]=x;
    return st;
}

int sdo(int p, int q)
{
    int m=divide(p,q);
    if (k==m)
        return a[k];
    if (m>k)
        return sdo(p,m-1);
    return sdo(m+1,q);
}

int main()
{
    srand(time(NULL));
    fin >> n >> k;
    for (i=1; i<=n; i++)
        fin >> a[i];
    fout << sdo(1,n) << '\n';
}