Merge Sort in Go

Welcome to the Merge Sort in Go page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

package main

import (
    "encoding/json"
    "fmt"
    "os"
    "regexp"
    "strconv"
    "strings"
)

func mergeSort(list []int) []int {
    var doMergeSort func(lst [][]int) [][]int
    doMergeSort = func(lst [][]int) [][]int {
        if len(lst) <= 0 {
            return [][]int{}
        }
        if len(lst) == 1 {
            return lst
        }
        return doMergeSort(append([][]int{merge(lst[0], lst[1])}, doMergeSort(lst[2:])...))
    }
    return doMergeSort(split(list))[0]
}

func split(list []int) (splitList [][]int) {
    for _, i := range list {
        splitList = append(splitList, []int{i})
    }
    return
}

func merge(list1 []int, list2 []int) []int {
    if len(list1) <= 0 {
        return list2
    }
    if len(list2) <= 0 {
        return list1
    }
    if list1[0] < list2[0] {
        return append(list1[:1], merge(list1[1:], list2)...)
    }
    return append(list2[:1], merge(list1, list2[1:])...)
}

func strToSliceInt(strList string) []int {
    list := regexp.MustCompile(", ?").Split(strList, -1)
    if len(list) < 2 {
        exitWithError()
    }
    var nums []int
    for _, num := range list {
        n, err := strconv.Atoi(num)
        if err != nil {
            exitWithError()
        }
        nums = append(nums, n)
    }
    return nums
}

func sliceIntToString(list []int) (out string) {
    bytes, _ := json.Marshal(list)
    out = strings.Replace(string(bytes), ",", ", ", -1)
    out = strings.Trim(out, "[]")
    return
}

func exitWithError() {
    fmt.Println("Usage: please provide a list of at least two integers to sort in the format \"1, 2, 3, 4, 5\"")
    os.Exit(1)
}

func main() {
    if len(os.Args) != 2 {
        exitWithError()
    }

    nums := strToSliceInt(os.Args[1])
    nums = mergeSort(nums)
    fmt.Println(sliceIntToString(nums))
}

Merge Sort in Go was written by:

• Parker Johansen

If you see anything you'd like to change or update, please consider contributing.

Note: The solution shown above is the current solution in the Sample Programs repository as of Mar 25 2019 19:45:18. The solution was first committed on Mar 17 2019 18:00:21. As a result, documentation below may be outdated.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.