Cod sursa(job #2537102)

Utilizator stelian2000Stelian Chichirim stelian2000 Data 3 februarie 2020 00:39:55
Problema Statistici de ordine Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.82 kb
#include <cstdio>
#include <algorithm>
#include <ctime>
 
using namespace std;
 
int v[3000010];
 
int random(int a,int b)
{
    return a+(1LL*rand()*rand())%(b-a+1);
}
 
void al_k_lea_min(int k,int st,int dr)
{
    if(st>=dr) return;
    int i=st,j=dr,a=v[random(st,dr)];
    while(i<=j)
    {
        while(v[i]<a) i++;
        while(v[j]>a) j--;
        if(i<=j)
        {
            swap(v[i],v[j]);
            i++;
            j--;
        }
    }
    if(k<=j-st+1) al_k_lea_min(k,st,j);
    else al_k_lea_min(k-(j-st+1),j+1,dr);
}
 
int main()
{
    freopen("sdo.in","r",stdin);
    freopen("sdo.out","w",stdout);
    int n,k;
    srand(time(0));
    scanf("%d%d",&n,&k);
    for(int i=1;i<=n;i++)
        scanf("%d",&v[i]);
    al_k_lea_min(k,1,n);
    printf("%d",v[k]);
    return 0;
}