Cod sursa(job #2378097)

Utilizator AngelescuHoriaAngelescu Horia AngelescuHoria Data 11 martie 2019 17:28:25
Problema Statistici de ordine Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.86 kb
#include <iostream>
#include <fstream>
#include <cstdlib>

using namespace std;

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

int v[3000001];

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

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

int main()
{
    int n, k, i;
    fin >> n >> k;
    for(i = 1; i <= n; i++)
        fin >> v[i];
    srand(time(0));
    for(int i = n; i > 0; i--)
    {
        int p = rand()%i;
        swap(v[i - 1], v[p]);
    }
    qs(v, 0, n, k);
        fout << v[k] << '\n';
    return 0;
}