Merge Sort in Go

main.go

package main

import (
	"fmt"
	"math/rand"
)

func fill(size int) []int {
	slice := make([]int, 0, size)
	for i := 0; i < size; i++ {
		slice = append(slice, int(rand.Float32()*10))
	}
	return slice
}

func merge(a []int, b []int) []int {
	aLen, bLen := len(a), len(b)
	totalLen := aLen + bLen
	c := make([]int, 0, totalLen)
	aIndex, bIndex := 0, 0
	for i := 0; i < totalLen; i++ {
		if aIndex == aLen {
			c = append(c, b[bIndex])
			bIndex++
		} else if bIndex == bLen {
			c = append(c, a[aIndex])
			aIndex++
		} else if a[aIndex] < b[bIndex] {
			c = append(c, a[aIndex])
			aIndex++
		} else {
			c = append(c, b[bIndex])
			bIndex++
		}
	}
	return c
}

func sort(unordered []int) []int {
	length := len(unordered)
	if length <= 1 {
		return unordered
	}
	pivot := length / 2
	a := unordered[0:pivot]
	b := unordered[pivot:length]
	return merge(sort(a), sort(b))
}

func main() {
	a, b, c := fill(100), fill(1), fill(0)
	fmt.Println(a)
	fmt.Println(sort(a))
	fmt.Println(b)
	fmt.Println(sort(b))
	fmt.Println(c)
	fmt.Println(sort(c))
}