Pagini recente » Cod sursa (job #2981578) | Cod sursa (job #48082) | Cod sursa (job #2553203) | Cod sursa (job #2831461) | Cod sursa (job #2198303)
#include <iostream>
#include <fstream>
#include <ctime>
using namespace std;
ifstream fin("sdo.in");
ofstream fout("sdo.out");
const int N= 3000001;
int v[N],k;
void partitie3(int st,int dr,int &p,int &u)
{
int pivot=v[st+rand%(dr-st+1)],i=st;
p=st;
u=dr;
while(i<=u)
{
if(v[i]<pivot)
swap(v[i++],v[p++]);
else if(v[i]>pivot)
swap(v[i],v[u--]);
else i++;
}
p--;
u++;
}
void qs(int st,int dr)
{
if(st>=dr)
return;
int p,u;
partitie3(st,dr,p,u);
if(k<=p && k>=st) qs(st,p);
else if(k>=u && k<=dr) qs(u,dr);
else if(k<u && k>p) return;
}
int main()
{
int n,i;
fin>>n>>k;
for(i=1;i<=n;i++)
fin>>v[i];
qs(1,n);
fout<<v[k];
}