Cod sursa(job #2307695)

Utilizator mihailescu_eduardMihailescu Eduard-Florin mihailescu_eduard Data 25 decembrie 2018 14:24:24
Problema Sortare prin comparare Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
// Sortare prin comparare folosind quicksort cu alegerea pivotului ultimul element
#include <fstream>
#include <random>
#include <time.h>
#include <algorithm>

using namespace std;

ifstream fin("algsort.in");
ofstream fout("algsort.out");

static const int NMAX = 5e5+5;

int n;
int v[NMAX];

int part(int arr[], int low, int high)
{
    int pivot1 = rand() % (high - low + 1) + low;
    int pivot2 = rand() % (high - low + 1) + low;
    int pivot3 = rand() % (high - low + 1) + low;

    int pivot = pivot1 + pivot2 + pivot3 - min(pivot1,min(pivot2,pivot3))
    -max(pivot1,max(pivot2,pivot3));

    while(low < high)
    {
        if(arr[low] >= arr[pivot])
            swap(arr[low], arr[pivot]);
        if(arr[high] <= arr[pivot])
            swap(arr[high],arr[pivot]);
        low++;
        high--;
    }
    return pivot;
}

void Quicksort(int arr[], int low, int high)
{
    if(low < high)
    {
        int pi = part(arr,low,high);

        Quicksort(arr,low, pi -1);
        Quicksort(arr, pi+1, high);
    }

}

void ReadInput()
{
    fin >> n;
    for(int i =1; i<= n;++i)
        fin >> v[i];
}
void PrintOutput()
{
    for(int i =1; i<= n;++i)
        fout << v[i] << " ";
}

int main()
{
    // Inititalise random seed
    srand(time(NULL));

    ReadInput();
    Quicksort(v,1,n);
    PrintOutput();
    return 0;
}