2020-10-09 22:58:41 +05:30
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/* Bubble Sort is an algorithm to sort an array. It
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2021-09-04 00:18:49 -07:00
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* compares adjacent element and swaps their position
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2020-10-09 22:58:41 +05:30
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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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2022-02-19 18:23:54 +06:00
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* Somehow if the array is sorted or nearly sorted then we can optimize bubble sort by adding a flag.
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2020-10-09 22:58:41 +05:30
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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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2021-01-24 23:29:50 +05:30
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* Animated Visual: https://www.toptal.com/developers/sorting-algorithms/bubble-sort
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2017-08-11 13:41:48 +05:30
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*/
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2020-05-04 11:58:44 +05:30
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2021-10-07 09:03:38 +02:00
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/**
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* Using 2 for loops.
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*/
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export function bubbleSort (items) {
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2020-05-04 11:58:44 +05:30
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const length = items.length
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2022-02-19 18:23:54 +06:00
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let noSwaps
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2020-10-09 22:58:41 +05:30
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2022-02-19 18:23:54 +06:00
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for (let i = length; i > 0; i--) {
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// flag for optimization
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noSwaps = true
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2020-05-04 11:58:44 +05:30
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// Number of passes
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2022-02-19 18:23:54 +06:00
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for (let j = 0; j < (i - 1); j++) {
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2020-05-04 11:58:44 +05:30
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// Compare the adjacent positions
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2022-02-19 18:23:54 +06:00
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if (items[j] > items[j + 1]) {
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2020-05-04 11:58:44 +05:30
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// Swap the numbers
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2022-02-19 18:23:54 +06:00
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[items[j], items[j + 1]] = [items[j + 1], items[j]]
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noSwaps = false
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2020-05-04 11:58:44 +05:30
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}
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2017-08-11 13:41:48 +05:30
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}
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2022-02-19 18:23:54 +06:00
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if (noSwaps) {
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break
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}
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2020-05-04 11:58:44 +05:30
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}
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2017-08-11 13:41:48 +05:30
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2020-10-09 22:58:41 +05:30
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return items
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}
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2017-10-16 11:23:46 +01:00
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2021-10-07 09:03:38 +02:00
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/**
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* Using a while loop and a for loop.
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*/
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export function alternativeBubbleSort (arr) {
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2020-05-04 11:58:44 +05:30
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let swapped = true
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2020-10-09 22:58:41 +05:30
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2020-05-04 11:58:44 +05:30
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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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2020-05-23 14:01:41 +08:00
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[arr[i], arr[i + 1]] = [arr[i + 1], arr[i]]
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2020-05-04 11:58:44 +05:30
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swapped = true
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}
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2017-10-16 12:56:02 +01:00
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}
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2020-05-04 11:58:44 +05:30
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}
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2020-10-09 22:58:41 +05:30
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2020-05-04 11:58:44 +05:30
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return arr
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2017-10-16 12:56:02 +01:00
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}
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