golang 归并排序算法

package main

import (
	"fmt"
)

var arr = []int{10, 5, 3, 9, 2, 3, 7, 8, 1, 25, 12}
var arrTmp = make([]int, len(arr))

func main() {
	fmt.Println(arr)
	MergeSort(arr, 0, len(arr)-1)
	fmt.Println(arr)
}

// MergeSort MergeSort
func MergeSort(arr []int, low, high int) []int {
	if low >= high {
		return make([]int, 0)
	}
	mid := low + (high-low)/2
	MergeSort(arr, low, mid)
	MergeSort(arr, mid+1, high)
	Merge(arr, low, mid, high)
	return arr
}

// Merge Merge
func Merge(arr []int, low, mid, high int) {
	i, j := low, mid+1
	for n := low; n <= high; n++ {
		arrTmp[n] = arr[n]
	}
	for n := low; n <= high; n++ {
		if i > mid {
			arr[n] = arrTmp[j]
			j++
		} else if j > high {
			arr[n] = arrTmp[i]
			i++
		} else if arrTmp[i] < arrTmp[j] {
			arr[n] = arrTmp[i]
			i++
		} else {
			arr[n] = arrTmp[j]
			j++
		}
	}
}