QuickSort

#include <bits/stdc++.h>
using namespace std;

void swap(int* a, int* b)
{
	int t = *a;
	*a = *b;
	*b = t;
}

int partition (int arr[], int low, int high)
{
	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);
}

void quickSort(int arr[], int low, int high)
{
	if (low < high)
	{
		int pi = partition(arr, low, high);
		quickSort(arr, low, pi - 1);
		quickSort(arr, pi + 1, high);
	}
}

int main()
{
	int arr[] = {10, 7, 8, 9, 1, 5};
	int n = sizeof(arr) / sizeof(arr[0]);
	cout<<"Before Sorting. \n";
	for(int i=0;i<n;i++){
	    cout<<arr[i]<<" ";
	}
	cout<<endl;
	quickSort(arr, 0, n - 1);
	cout << "Sorted array: \n";
	for(int i=0;i<n;i++){
	    cout<<arr[i]<<" ";
	}
	return 0;
}
//Best case: O(n*logn)
//Average case: O(n*logn)
//Worst case:O(n^2)