quicksort in code

1// A full c++ quicksort algorithm no bs
2// quicksort in code
3
4#include <iostream>
5
6using namespace std;
7
8void QuickSort(int arr[], int start, int end);
9int Partition(int arr[], int start, int end);
10void SwapArrMem(int arr[], int a, int b);
11
12int main()
13{
14
15	int arr[4]; //change the size of the array to your desired array size
16
17	cout << "enter " << sizeof(arr) / sizeof(arr[0]) << " numbers. press enter after input" << endl;
18
19	for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++)
20	{
21		
22		cin >> arr[i];
23	}
24
25	cout << endl << "The sorted numbers are:" << endl << endl;
26
27
28
29	QuickSort(arr, 0, sizeof(arr) / sizeof(arr[0]) - 1);
30
31	for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++)
32	{
33		cout << arr[i] << endl;
34	}
35
36}
37
38void QuickSort(int arr[], int start, int end)
39{
40	if (start >= end) return;
41
42	int index = Partition(arr, start, end);
43	QuickSort(arr, start, index - 1);
44	QuickSort(arr, index + 1, end);
45}
46
47int Partition(int arr[], int start, int end)
48{
49	int pivotindex = start;
50	int pivotvalue = arr[end];
51	for (int i = start; i < end; i++)
52	{
53		if (arr[i] < pivotvalue)
54		{
55			SwapArrMem(arr, i, pivotindex);
56			pivotindex++;
57		}
58	}
59	SwapArrMem(arr, pivotindex, end);
60	return pivotindex;
61}
62
63void SwapArrMem(int arr[], int a, int b)
64{
65	int temp = arr[a];
66	arr[a] = arr[b];
67	arr[b] = temp;
68}