diff --git a/Sorts/BubbleSort.js b/Sorts/BubbleSort.js index 3232991d1d..9f2fecac13 100644 --- a/Sorts/BubbleSort.js +++ b/Sorts/BubbleSort.js @@ -1,11 +1,40 @@ -/* Bubble Sort is a algorithm to sort an array. It -* compares adjacent element and swaps thier position -* The big O on bubble sort in worst and best case is O(N^2). - * Not efficient. +/* Bubble Sort is an algorithm to sort an array. It +* compares adjacent element and swaps thier position +* The big O on bubble sort in worst and best case is O(N^2). +* Not efficient. +* +* In bubble sort, we keep iterating while something was swapped in +* the previous inner-loop iteration. By swapped I mean, in the +* inner loop iteration, we check each number if the number proceeding +* it is greater than itself, if so we swap them. +* +* Wikipedia: https://en.wikipedia.org/wiki/Bubble_sort */ +/* +* Doctests +* +* > bubbleSort([5, 4, 1, 2, 3]) +* [1, 2, 3, 4, 5] +* > bubbleSort([]) +* [] +* > bubbleSort([1, 2, 3]) +* [1, 2, 3] +* +* > alternativeBubbleSort([5, 4, 1, 2, 3]) +* [1, 2, 3, 4, 5] +* > alternativeBubbleSort([]) +* [] +* > alternativeBubbleSort([1, 2, 3]) +* [1, 2, 3] +*/ + +/* +* Using 2 for loops +*/ function bubbleSort (items) { const length = items.length + for (let i = (length - 1); i > 0; i--) { // Number of passes for (let j = (length - i); j > 0; j--) { @@ -16,31 +45,28 @@ function bubbleSort (items) { } } } -} - -// Implementation of bubbleSort -var ar = [5, 6, 7, 8, 1, 2, 12, 14] -// Array before Sort -console.log('-----before sorting-----') -console.log(ar) -bubbleSort(ar) -// Array after sort -console.log('-----after sorting-----') -console.log(ar) + return items +} -/* alternative implementation of bubble sort algorithm. - Using a while loop instead. For educational purposses only - */ /* -*In bubble sort, we keep iterating while something was swapped in -*the previous inner-loop iteration. By swapped I mean, in the -*inner loop iteration, we check each number if the number proceeding -*it is greater than itself, if so we swap them. +* Implementation of 2 for loops method */ +var array1 = [5, 6, 7, 8, 1, 2, 12, 14] +// Before Sort +console.log('\n- Before Sort | Implementation using 2 for loops -') +console.log(array1) +// After Sort +console.log('- After Sort | Implementation using 2 for loops -') +console.log(bubbleSort(array1)) +console.log('\n') +/* +* Using a while loop and a for loop +*/ function alternativeBubbleSort (arr) { let swapped = true + while (swapped) { swapped = false for (let i = 0; i < arr.length - 1; i++) { @@ -50,12 +76,18 @@ function alternativeBubbleSort (arr) { } } } + return arr } -// test -console.log('-----before sorting-----') -var array = [10, 5, 3, 8, 2, 6, 4, 7, 9, 1] -console.log(array) -console.log('-----after sorting-----') -console.log(alternativeBubbleSort(array)) +/* +* Implementation of a while loop and a for loop method +*/ +var array2 = [5, 6, 7, 8, 1, 2, 12, 14] +// Before Sort +console.log('\n- Before Sort | Implementation using a while loop and a for loop -') +console.log(array2) +// After Sort +console.log('- After Sort | Implementation using a while loop and a for loop -') +console.log(alternativeBubbleSort(array2)) +console.log('\n')