Insertion Sort in Mathematica

Published on 28 April 2022 (Updated: 02 February 2023)

Insertion Sort in Mathematica

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

Current Solution

(* Code *)

(* The actual insertion sort which takes and returns a Mathematica list is easy: *)

insertionSort = l \[Function] NestWhile[
    (* insert a single element *)
    Module[{li = Length[#] + 1},
      Insert[
       #, (* sorted list so far *)
       l[[li]],(* next element to insert *)
       First[FirstPosition[#, (* at what index to insert it *)
         v_ /; v > l[[li]], (* element that is greater than the element to insert *)
         {li},(* or else insert at end *)
         {1}, Heads -> False](* only look at list elements *)]]] &,
    
    (* start with an empty sorted list *)
    {},
    
    (* while there are still elements left to insert into the sorted list *)
    Length[#] < Length[l] &];

(* The outer function provides the 'user interface': *)

insertionSortMain = Function[{l},
   Module[{e = "Usage: please provide a list of at least two integers to sort in the format \"1, 2, 3, 4, 5\""},
    Catch[
     StringRiffle[(* format output as required *)
      insertionSort @@ Map[
        (* convert string to integer, or throw *)
        s \[Function] If[StringMatchQ[s, DigitCharacter ..],
          FromDigits[s],
          Throw[e]],
        (* construct arguments to insertion sort: list of items *)
        {If[Length[#] > 1, #, Throw[e]] &[StringSplit[l, ", "]]},
        {-1} (* at each leaf *)],
      ", "]]]];


(* Valid Tests *)

Print /@ insertionSortMain /@ {
    "4, 5, 3, 1, 2",
    "4, 5, 3, 1, 4, 2",
    "1, 2, 3, 4, 5",
    "9, 8, 7, 6, 5, 4, 3, 2, 1"
    };


(* Invalid Tests *)

insertionSortMain[""]
insertionSortMain["1"]
insertionSortMain["4 5 3"]

Insertion Sort in Mathematica was written by:

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

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.