Cod sursa(job #2587902)

Utilizator Katherine456719Swan Katherine Katherine456719 Data 23 martie 2020 19:01:36
Problema Statistici de ordine Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.91 kb
#include <bits/stdc++.h>
#define nmax 3000005
using namespace std;
ifstream f("sdo.in");
ofstream g("sdo.out");
int v[nmax];
int poz(int l,int r)
{
    int i=l-1,j=r+1;
    int piv=rand() % (r - l + 1) + l;
    while(1)
    {
        do
        {
            i++;
        }while(v[i]<v[piv]);
        do
        {
            j--;
        }while(v[j]>v[piv]);
        if(i<j)
            swap(v[i],v[j]);
        else
           return j;
    }
    return 0;
}
void quicksort(int l,int r,int k)
{
    if(l>=r)
        return;
    int m,t;
    t=poz(l,r);
    m=t-l+1;
    if(m>=k)
        quicksort(l,t,k);
    else
        quicksort(t+1,r,k-m);
}
int main()
{
    ios::sync_with_stdio(false);
    f.tie(nullptr);
    g.tie(nullptr);
    srand(time(NULL));
    int n,k;
    f>>n>>k;
    for(int i=1; i<=n; i++)
        f>>v[i];
    quicksort(1,n,k);
    g<<v[k];
    return 0;
}