Cod sursa(job #2507505)

Utilizator gabriel_froneaFronea Gabriel gabriel_fronea Data 10 decembrie 2019 13:10:15
Problema Statistici de ordine Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.79 kb
#include <fstream>

using namespace std;

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

int v[3000001];

int partitie(int v[], int st, int dr)
{
    int p=st;
    for(int i=st; i<dr; i++)
    {
        if(v[i]<=v[dr])
        {
            swap(v[i], v[p++]);
        }
    }
    swap(v[p], v[dr]);
    return p;
}

void qs(int v[], int st, int dr, int k)
{
    if(st>=dr)
    {
        return;
    }
    int p=partitie(v, st, dr);
    if(k<p)
        qs(v, st, p-1, k);
    if(k>p)
        qs(v, p+1, dr, k);
}

int main()
{
    int n, k;
    in>>n>>k;
    int st=0;
    int dr=n-1;
    for(int i=0; i<n; i++)
    {
        in>>v[i];
    }
    for (int i = n; i > 0; i--)
    {
        int p = rand() % i;
        swap(v[p], v[i-1]);
    }
    k--;
    qs(v, st, dr, k);
    out<<v[k];
    return 0;
}