Cod sursa(job #1513285)

Utilizator retrogradLucian Bicsi retrograd Data 29 octombrie 2015 11:56:07
Problema Statistici de ordine Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.64 kb
#include <fstream>
#include <cstdlib>

using namespace std;

int A[4000000];

int nth(int *A, int n, int k) {
    if(n == 1) return A[1];

    swap(A[n], A[rand() % n + 1]);

    int poz = 1;
    for(int i=1; i<n; i++) {
        if(A[i] <= A[n])
            swap(A[i], A[poz++]);
    }
    swap(A[n], A[poz]);

    if(k == poz) return A[poz];
    if(poz > k) return nth(A, poz-1, k);
    return nth(A+poz, n-poz, k-poz);
}

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

    int n, k;
    fin>>n>>k;

    for(int i=1; i<=n; i++)
        fin>>A[i];
    fout<<nth(A, n, k);

    return 0;
}