quicksort.cpp

#include <bits/stdc++.h>
#include <stdlib.h>
#include<time.h>
#include<random>
#include<ctime>
using namespace std;
int partition(int arr[], int low, int high)
{
    // pivot
    int pivot = arr[high];
   
    int i = (low - 1);
 
    for (int j = low; j <= high - 1; j++)
    {
        if (arr[j] <= pivot) {
 
            i++;
            swap(arr[i], arr[j]);
        }
    }
    swap(arr[i + 1], arr[high]);
    return (i + 1);
}
int partition_r(int arr[], int low, int high)
{
    int random = low + rand() % (high - low);
 
    swap(arr[random], arr[high]);
 
    return partition(arr, low, high);
}
void quickSort(int arr[], int low, int high)
{
    if (low < high) {
        int pi = partition_r(arr, low, high);
        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}
void printArray(int arr[], int size)
{
    int i;
    for (i = 0; i < size; i++)
        printf("%d ", arr[i]);
    printf("\n");
}
int main()
{
    int n;
    cin>>n;
    int arr[n];
    for(int i=0;i<n;i++)
        cin>>arr[i];
    quickSort(arr, 0, n - 1);
    printf("Sorted array: \n");
    printArray(arr, n);
    return 0;
}