A simple c++ program to sort an array using Quick sort algorithm.

quickSort.cpp

/*
Name: Quick Sort
Author: Gaurav Sharma
Date: 27-04-19 18:01
Description: A simple c++ program to sort an array using Quick sort algorithm.
*/
#include <iostream>
#include <conio.h>
#include <time.h>

#define NO_RUNS 100
int count = 0;

using namespace std;

void circularShift(int *Arr, const int &start, const int &end)
{
    int temp = Arr[end];
    for (int i = end - 1; i >= start; --i)
    {
        Arr[i + 1] = Arr[i];
    }
    Arr[start] = temp;
}

int partition(int *Arr, const int &start, const int &end)
{
    int piv = start; // select first element as pivot.
    int var = start + 1;
    for (int i = start; i < end; ++i)
    {
        ++count;
        if (Arr[piv] > Arr[var])
        {
            circularShift(Arr, piv++, var++);
        }
        else
            ++var;
    }
    return piv;
}

void quickSort(int *Arr, int start, int end)
{
    if (start < end)
    {
        int piv_pos = partition(Arr, start, end);
        quickSort(Arr, start, piv_pos - 1);
        quickSort(Arr, piv_pos + 1, end);
    }
}

int main()
{
    srand(time(0));
    int *compr_array = new int[NO_RUNS];

    cout << "\nquick sort: \n";
    for (int k = 0; k < NO_RUNS; k++)
    {
        cout << "\n\nRUN " << k + 1;
        int size = 5 + (rand() % (15 - (5) + 1));

        cout << "\n\nsize : " << size;
        int *arr = new int[size];

        cout << "\n\nInitial array : ";
        for (int i = 0; i < size; i++)
        {
            arr[i] = -100 + (rand() % (100 - (-100) + 1));
            cout << "  " << arr[i];
        }

        quickSort(arr, 0, size - 1);
        int no_comp = count;
        compr_array[k] = no_comp;

        cout << "\n\ntotal no of comparisons : " << no_comp;
        cout << "\n\nSorted array : \n";
        for (int i = 0; i < size; i++)
        {
            cout << "\n"
                 << arr[i];
        }
    }

    getch();
    return 0;
}