Introduction

Insertion sort is another simple algorithm.

How it works

Insertion sort works similar to how you would sort a set of playing cards in your hand. When an element is not in the correct place, it is swapped until it is in the correct position.

Example

function insertionSort(arr) {
  for (let i = 1; i < arr.length; i++) {
    const key = arr[i];
    let j = i - 1;
    while (j >= 0 && arr[j] > key) {
      arr[j + 1] = arr[j];
      j = j - 1;
    }
    arr[j + 1] = key;
  }
  return arr;
}

console.log(insertionSort([4, 1, 0, 51, 23, 10, 9, 15]));

Lesson task

Insertion sort is fairly simple once you have taken the time to understand how it works.

Goal

For you to be able to write an Insertion sort on your own.

Brief

Complete the Level 1 process.

NOTE: Lesson tasks do not get submitted on Moodle and are not assessed by tutors. They are mainly there for you to practise what you have learned in the lesson.

Level 1 process

  1. Read through and run the example code, console logging where you’d like to get a better understanding.

  2. Once you have a good understanding, try to recreate the Insertion sort on your own.

Additional resources

GeeksforGeeks: Insertion Sort

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