Cod sursa(job #2132519)

Utilizator arabtrappinTudor Bursuc arabtrappin Data 15 februarie 2018 20:19:13
Problema Statistici de ordine Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <fstream>
#include <cstdlib>
#include <ctime>
#define DMAX 4000001
using namespace std;
int v[DMAX];
int n,k;
ifstream fin("sdo.in");
ofstream fout("sdo.out");
int divi(int st,int dr)
{
    int poz=st+rand()%(dr-st+1);
 int piv;
 piv=v[poz]; v[poz]=v[st]; v[st]=piv;
 piv=v[st];
 while (st<dr)
    {//liber la stanga
     while (st<dr && v[dr]>=piv)dr--;
     v[st]=v[dr];
     //liber la dreapta
     while(st<dr && v[st]<=piv)st++;
     v[dr]=v[st];
    }

 v[st]=piv;

 return st;
}
int ksmallest(int st,int dr)
{
    int piv;
    piv=divi(st,dr);
    if(k<piv)return ksmallest(st,piv);
    else if(k>piv)return ksmallest(piv+1,dr);
    else return v[piv];
}
int main()
{int i;
 srand(time(0));
 fin>>n>>k;
    for(i=1;i<=n;i++)
        fin>>v[i];
    fout<<ksmallest(1,n);
    return 0;
}