Cod sursa(job #1465173)

Utilizator fanache99Constantin-Buliga Stefan fanache99 Data 26 iulie 2015 17:29:02
Problema Statistici de ordine Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include<cstdio>
#include<ctime>
#include<cstdlib>
using namespace std;
int v[3000010];
void swap(int i,int j){
    int aux=v[i];
    v[i]=v[j];
    v[j]=aux;
}
int partitionare(int left,int right){
    int i=left,j=right,pivot=v[left+rand()%(right-left+1)];
    while(1){
        while(v[i]<pivot)
            i++;
        while(v[j]>pivot)
            j--;
        if(i<j)
            swap(i,j);
        else
            return j;
    }
}
void quick_sort(int left,int right,int k){
    if(left==right)
        return;
    int poz=partitionare(left,right);
    if(poz-left+1>=k)
        quick_sort(left,poz,k);
    else
        quick_sort(poz+1,right,k-poz+left-1);
}
int main(){
    freopen("sdo.in","r",stdin);
    freopen("sdo.out","w",stdout);
    int n,i,k;
    scanf("%d%d",&n,&k);
    srand(time(0));
    for(i=1;i<=n;i++)
        scanf("%d",&v[i]);
    quick_sort(1,n,k);
    printf("%d",v[k]);
    return 0;
}