Cod sursa(job #1019427)

Utilizator RampageSergiu Caraian Rampage Data 31 octombrie 2013 02:01:08
Problema Statistici de ordine Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 0.57 kb
#include <fstream>
#include <cstdlib>
using namespace std;

ifstream f("sdo.in");
ofstream g("sdo.out");

int v[3000000],n,k;

int partition(int ls, int rd)
{
	int p = v[rand() % rd+1];
	while (ls<=rd)
	{
		while(v[ls]<p)
			ls++;
		while(v[rd]>p)
			rd--;
		if(ls<=rd)
		{
			int aux = v[ls];
			v[ls]=v[rd];
			v[rd]=aux;
			ls++;
			rd--;
		}
	}
	return ls;
}

void qs(int ls, int rd)
{
	if (ls<rd)
	{
		int p = partition(ls,rd); 
		if (k<p)
			qs(ls,p-1);
		else 
			qs(p,rd);
	}
}   

int main()
{
	f>>n>>k;
	for (int i=1; i<=n; ++i)
		f>>v[i];

	qs(1,n);
	g<<v[k];
	return 0;
}