Cod sursa(job #657835)

Utilizator lavinia_nLavinia Nastase lavinia_n Data 7 ianuarie 2012 15:10:40
Problema Statistici de ordine Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.81 kb
#include<stdio.h>
#include<cstdlib>

int a[3000005],n,k;

void citire(){
	scanf("%d%d",&n,&k);
	for(int i=1;i<=n;i++)
		scanf("%d",&a[i]);
}

int pivot (int s, int d) {
    int i=s-1, j=d-1, piv=a[s+(rand()%(d-s+1))];
    while(i<j) {
               while(a[i]<piv)
                              i++;
               while(a[j]>piv)
                              j--;
               if(i<j)
                      a[i]=a[i]^a[j]^(a[j]=a[i]);
               else return j;
               }
    return 0;
}

void quick(int i,int j,int k){
	int p=pivot(i-1,j+1);
	if(i==j)
		return;
	else
	if(k>p)
		quick(p+1,j,k);
	else
		quick(i,p,k);
}

int main(){
	freopen("sdo.in","r",stdin);
	freopen("sdo.out","w",stdout);
	citire();
	quick(1,n,k);
	printf("%d",a[k]);
	return 0;
}