Cod sursa(job #2277151)

Utilizator dianamichesaRosu Diana Michesa dianamichesa Data 5 noiembrie 2018 20:24:02
Problema Statistici de ordine Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <iostream>
#include <fstream>
#include <random>
using namespace std;
ifstream f("sdo.in");
ofstream g("sdo.out");
const int N = 3000001;
int n, v[N], k;
int partitie (int v[], int st, int dr) {
    int ra=st+rand()%(dr-st+1);
    int rb=st+rand()%(dr-st+1);
    int rc=st+rand()%(dr-st+1);
    if(v[ra]>v[rb])
    {
        swap(ra,rb);
    }
    if(v[ra]>v[rc])
    {
        swap(ra,rc);
    }
    if(v[rb]>v[rc])
    {
        swap(rb,rc);
    }
    int poz=rb;
    swap(v[dr],v[poz]);
    int pivot = v[dr];
    int i=st-1;
    int j=dr+1;
    while(1)
    {
        do
        {
            i++;
        }
        while(v[i]<pivot);
        do
        {
            j--;
        }
        while(v[j]>pivot);
        if(i>=j)
        {
            return j;
        }
        swap(v[i],v[j]);
    }
}
void sdo (int v[], int st, int dr, int k) {
    if(st >= dr)
        return;
    int part = partitie (v, st, dr);
    int x = part - st + 1;
    if(x >= k)
        sdo (v, st, part, k);
    else
        sdo (v, part + 1, dr, k - x);
}
void afisare (int v[]) {
    for(int i = 1; i <= n; i ++)
        g << v[i] << ' ';
}
int main()
{
    f >> n >> k;
    for(int i = 1; i <= n; i ++)
        f >> v[i];
    sdo (v, 1, n, k);
    g << v[k];
    return 0;
}