Cod sursa(job #1779990)

Utilizator dragos_vecerdeaVecerdea Dragos dragos_vecerdea Data 15 octombrie 2016 19:20:17
Problema Statistici de ordine Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <time.h>
using namespace std;
FILE *fin = fopen("sdo.in" , "r");
FILE *fout = fopen("sdo.out" , "w");
#define MAX 3000000
int v[MAX+1];
int n , k;
int pivot(int st , int dr , int p)
{
    int poz=st;
    for(int i=st;i<=dr;i++)
    {
        if(v[p]>v[i]) poz++;
    }
    swap(v[poz] , v[p]);
    int i1 , i2;
    i1=st;
    i2=poz+1;
    while(i1<poz && i2<=dr)
    {
        if(v[i1]>v[i2])
        {
            swap(v[i1] , v[i2]);
            i1++;i2++;
        }
        else
        {
            if(v[i1]<v[poz])i1++;
            if(v[i2]>v[poz])i2++;
        }
    }
    return poz;
}
void qs(int st , int dr)
{
    if(st<dr)
    {
        int p;
        srand (time(NULL));
        p = st+rand()%(dr-st);
        p=pivot(st , dr , p);
        if(k==p) return;
        else
        {
            if(k<p) qs(st , p-1);
            else  qs(p+1,dr);
        }

    }
    else return;
}
int main()
{
    fscanf(fin , "%d%d\n" , &n , &k);
    for(int i=1;i<=n;i++)
    {
        fscanf(fin , "%d" , &v[i]);
    }
    qs(1 , n);
     fprintf(fout , "%d" , v[k]);
    return 0;
}