Quick sort

package main

import (
	"fmt"
	"math/rand"
	"time"

	"golang.org/x/exp/constraints"
)

// O(nlogn) Expected
func QuickSort[T constraints.Ordered](list []T, start int, end int) {

	if start < 0 || end <= start || int(end) >= len(list) {
		return
	}
	last := list[end]

	// partition
	pointer := start
	for j := start; j < end; j++ {
		if list[j] < last {
			list[j], list[pointer] = list[pointer], list[j]
			pointer++
		}
	}
	list[end], list[pointer] = list[pointer], list[end]

	QuickSort(list, start, pointer-1)
	QuickSort(list, pointer+1, end)

}

// O(nlogn) Expected
func RandomizedQuickSort[T constraints.Ordered](list []T, start int, end int) {

	if start < 0 || end <= start || int(end) >= len(list) {
		return
	}

	rndIndex := start + rand.Intn(end-start+1)
	list[end], list[rndIndex] = list[rndIndex], list[end]

	// partition
	pointer := start
	for j := start; j < end; j++ {
		if list[j] < list[end] {
			list[j], list[pointer] = list[pointer], list[j]
			pointer++
		}
	}
	list[end], list[pointer] = list[pointer], list[end]

	QuickSort(list, start, pointer-1)
	QuickSort(list, pointer+1, end)

}

func main() {

	rand.Seed(time.Now().Unix())

	list := []int{1, 10, 15, -5, 3, -10, 3, 12, 2, 30, 0}

	QuickSort(list, 0, len(list)-1)
	fmt.Println(list)

	RandomizedQuickSort(list, 0, len(list)-1)
	fmt.Println(list)
}