package main

import "fmt"

func main() {

	arr := []int{4, 1, 3, 2, 5}
	result := QuickSort(arr)
	
	fmt.Println(result)
}

func QuickSort(arr []int) []int {

	if len(arr) <= 1 {
		return arr
	}

	return quickSort(arr, 0, len(arr)-1)
}

func quickSort(arr []int, low, high int) []int {

	if low >= high {
		return arr
	}

	partitionVal := partition(arr, low, high)
	arr = quickSort(arr, low, partitionVal-1)
	arr = quickSort(arr, partitionVal+1, high)

	return arr
}

func partition(arr []int, low, high int) int {
	
	pivot := arr[high]
	i := low - 1

	for j := low; j < high; j++ {
		if arr[j] < pivot {
			i += 1
			arr[i], arr[j] = arr[j], arr[i]
		}
	}
	arr[i+1], arr[high] = arr[high], arr[i+1]
	
    return i + 1
}

[1 2 3 4 5]