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94 lines
2.2 KiB
JavaScript
94 lines
2.2 KiB
JavaScript
/* Bubble Sort is an algorithm to sort an array. It
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* compares adjacent element and swaps thier position
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* The big O on bubble sort in worst and best case is O(N^2).
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* Not efficient.
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*
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* In bubble sort, we keep iterating while something was swapped in
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* the previous inner-loop iteration. By swapped I mean, in the
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* inner loop iteration, we check each number if the number proceeding
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* it is greater than itself, if so we swap them.
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*
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* Wikipedia: https://en.wikipedia.org/wiki/Bubble_sort
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*/
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/*
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* Doctests
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*
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* > bubbleSort([5, 4, 1, 2, 3])
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* [1, 2, 3, 4, 5]
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* > bubbleSort([])
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* []
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* > bubbleSort([1, 2, 3])
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* [1, 2, 3]
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*
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* > alternativeBubbleSort([5, 4, 1, 2, 3])
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* [1, 2, 3, 4, 5]
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* > alternativeBubbleSort([])
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* []
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* > alternativeBubbleSort([1, 2, 3])
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* [1, 2, 3]
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*/
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/*
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* Using 2 for loops
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*/
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function bubbleSort (items) {
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const length = items.length
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for (let i = (length - 1); i > 0; i--) {
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// Number of passes
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for (let j = (length - i); j > 0; j--) {
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// Compare the adjacent positions
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if (items[j] < items[j - 1]) {
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// Swap the numbers
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[items[j], items[j - 1]] = [items[j - 1], items[j]]
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}
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}
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}
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return items
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}
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/*
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* Implementation of 2 for loops method
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*/
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var array1 = [5, 6, 7, 8, 1, 2, 12, 14]
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// Before Sort
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console.log('\n- Before Sort | Implementation using 2 for loops -')
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console.log(array1)
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// After Sort
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console.log('- After Sort | Implementation using 2 for loops -')
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console.log(bubbleSort(array1))
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console.log('\n')
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/*
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* Using a while loop and a for loop
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*/
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function alternativeBubbleSort (arr) {
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let swapped = true
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while (swapped) {
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swapped = false
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for (let i = 0; i < arr.length - 1; i++) {
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if (arr[i] > arr[i + 1]) {
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[arr[i], arr[i + 1]] = [arr[i + 1], arr[i]]
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swapped = true
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}
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}
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}
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return arr
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}
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/*
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* Implementation of a while loop and a for loop method
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*/
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var array2 = [5, 6, 7, 8, 1, 2, 12, 14]
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// Before Sort
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console.log('\n- Before Sort | Implementation using a while loop and a for loop -')
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console.log(array2)
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// After Sort
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console.log('- After Sort | Implementation using a while loop and a for loop -')
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console.log(alternativeBubbleSort(array2))
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console.log('\n')
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