Posted onOct 25, 2020 • Edited onDec 17, 2021

Sorting Algorithms in Go

#go #sort #tutorial

Hey, Dev.to community!

As a little project, I've written some famous sort algorithms using Go. I hope this would be useful for you!

Bubble Sort

Bubble sort is a very easy algorithm to follow. You need to check every element of an array against the next element to see if it is larger, if so, you need to swap them. You should do this task as many times as finally there wouldn't be any swap action needed.

packagemainimport"fmt"funcmain(){varn=[]int{1,39,2,9,7,54,11}varisDone=falsefor!isDone{isDone=truevari=0fori<len(n)-1{ifn[i]>n[i+1]{n[i],n[i+1]=n[i+1],n[i]isDone=false}i++}}fmt.Println(n)}

Recursive Bubble Sort

Recursive bubble sort is a variation of the normal bubble sort (also knows as iterative bubble sort). This works the same as the iterative bubble sort with no extra advantages over time or complexity XD. But this will improve your understanding of bubble sort and recursion:

packagemainimport"fmt"funcbubbleSort(arr[]int,sizeint)[]int{ifsize==1{returnarr}vari=0fori<size-1{ifarr[i]>arr[i+1]{arr[i],arr[i+1]=arr[i+1],arr[i]}i++}bubbleSort(arr,size-1)returnarr}funcmain(){varn=[]int{1,39,2,9,7,54,11}fmt.Println(bubbleSort(n,len(n)))}

Insertion Sort

Insertion sort is a famous sorting algorithm that works like sorting a deck of cards in hand. As you proceed through the elements of an array you would move it back until it is in the correct place.

packagemainimport"fmt"funcmain(){varn=[]int{1,39,2,9,7,54,11}vari=1fori<len(n){varj=iforj>=1&&n[j]<n[j-1]{n[j],n[j-1]=n[j-1],n[j]j--}i++}fmt.Println(n)}

Selection Sort

Selection sort is quite interesting and yet simple. What you need to do is simply replace the current element in iteration by the lowest value on the right. As you go further the left part of the array is sorted, and you don't need to check for the last element.

packagemainimport"fmt"funcmain(){varn=[]int{1,39,2,9,7,54,11}vari=1fori<len(n)-1{varj=i+1varminIndex=iifj<len(n){ifn[j]<n[minIndex]{minIndex=j}j++}ifminIndex!=i{vartemp=n[i]n[i]=n[minIndex]n[minIndex]=temp}i++}fmt.Println(n)}

Merge Sort

Merge is a quite fast sorting algorithm. In a merge sort, you should utilize the divide-and-conquer practice. First, you'll divide the passed array by 2 recursively, until you reach the length of 1, then you should merge them. To merge two arrays that we know are already sorted themselves you can implement a simple function called merge.

packagemainimport"fmt"funcmerge(fp[]int,sp[]int)[]int{varn=make([]int,len(fp)+len(sp))varfpIndex=0varspIndex=0varnIndex=0forfpIndex<len(fp)&&spIndex<len(sp){iffp[fpIndex]<sp[spIndex]{n[nIndex]=fp[fpIndex]fpIndex++}elseifsp[spIndex]<fp[fpIndex]{n[nIndex]=sp[spIndex]spIndex++}nIndex++}forfpIndex<len(fp){n[nIndex]=fp[fpIndex]fpIndex++nIndex++}forspIndex<len(sp){n[nIndex]=sp[spIndex]spIndex++nIndex++}returnn}funcmergeSort(arr[]int)[]int{iflen(arr)==1{returnarr}varfp=mergeSort(arr[0:len(arr)/2])varsp=mergeSort(arr[len(arr)/2:])returnmerge(fp,sp)}funcmain(){varn=[]int{1,39,2,9,7,54,11,8}fmt.Println(mergeSort(n))}

Counting Sort

Counting sort is a really simple yet complicated sorting algorithm. To understand how counting sort works you can watch the video below from GeekforGeeks:

Here is the Go code:

packagemainimport"fmt"funccountSort(arr[]int)[]int{varmax=arr[0]vari=1fori<len(arr){ifarr[i]>max{max=arr[i]}i++}varindices=make([]int,max+1)varj=0forj<len(arr){indices[arr[j]]++j++}vark=1fork<len(indices){indices[k]+=indices[k-1]k++}varresult=make([]int,len(arr))varm=0form<len(arr){result[indices[arr[m]]-1]=arr[m]indices[arr[m]]--m++}returnresult}funcmain(){varn=[]int{1,39,2,9,7,54,11}fmt.Println(countSort(n))}

I will complete this list by time.

BTW! Check out my free Node.js Essentials E-book here:

NodeJS Essentials | Free E-Book

Adnan Babakan (he/him) ・ Sep 11 '20

#node#javascript#books

Top comments(5)

Jacob Alberty

Joined
Dec 15, 2021

• Dec 15 '21

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Your bubble sort contains an error. The output is[1 2 9 7 39 11 54] which is clearly not fully sorted. It only does one iteration. Just need to add anisDone = false inside of the if statement

packagemainimport"fmt"funcmain(){varn=[]int{1,39,2,9,7,54,11}varisDone=falsefor!isDone{isDone=truevari=0fori<len(n)-1{ifn[i]>n[i+1]{n[i],n[i+1]=n[i+1],n[i]isDone=false}i++}}fmt.Println(n)}