package main

import "fmt"

func main() {
	list := []int{5, 4, 0, 9, 7, 1, 3, 2, 4}
	fmt.Printf("Список до сортировки - %d\n", list)
	//sortedList := BubbleSort(list)
	//sortedList := MergeSort(list)
	sortedList := QuickSort(list)
	fmt.Printf("Список после сортировки - %d", sortedList)

}

func BubbleSort(list []int) []int {
	for i := 0; i < len(list); i++ {
		for j := 0; j < len(list)-i-1; j++ {
			if list[j] > list[j+1] {
				temp := list[j]
				list[j] = list[j+1]
				list[j+1] = temp
			}
		}
	}
	return list
}

func MergeSort(items []int) []int {
	if len(items) < 2 {
		return items
	}

	middle := len(items) / 2
	left := MergeSort(items[:middle])
	right := MergeSort(items[middle:])
	return Merge(left, right)
}

func Merge(left, right []int) []int {
	var result []int
	i := 0
	j := 0

	for i < len(left) && j < len(right) {
		if left[i] < right[j] {
			result = append(result, left[i])
			i++
		} else {
			result = append(result, right[j])
			j++
		}
	}

	for ; i < len(left); i++ {
		result = append(result, left[i])
	}

	for ; j < len(right); j++ {
		result = append(result, right[j])
	}

	return result
}

func QuickSort(arr []int) []int {
	if len(arr) <= 1 {
		return arr
	}

	pivot := arr[len(arr)/2]
	left := make([]int, 0)
	middle := make([]int, 0)
	right := make([]int, 0)

	for _, item := range arr {
		if item < pivot {
			left = append(left, item)
		} else if item == pivot {
			middle = append(middle, item)
		} else {
			right = append(right, item)
		}
	}

	return append(
		append(QuickSort(left), middle...),
		QuickSort(right)...,
	)
}