Merge pull request trekhleb#10 from albertstill/improve-bubble-sort

stop bubble sort revisiting already sorted elements

Author: trekhleb

src/algorithms/sorting/bubble-sort/BubbleSort.js

@@ -7,13 +7,13 @@ export default class BubbleSort extends Sort {
  // Clone original array to prevent its modification.
  const array = [...originalArray];
 
- for (let i = 0; i < array.length; i += 1) {
+ for (let i = 1; i < array.length; i += 1) {
  swapped = false;
 
  // Call visiting callback.
  this.callbacks.visitingCallback(array[i]);
 
- for (let j = 0; j < array.length - 1; j += 1) {
+ for (let j = 0; j < array.length - i; j += 1) {
  // Call visiting callback.
  this.callbacks.visitingCallback(array[j]);
 

src/algorithms/sorting/bubble-sort/__test__/BubbleSort.test.js

@@ -9,8 +9,8 @@ import {
 
 // Complexity constants.
 const SORTED_ARRAY_VISITING_COUNT = 20;
-const NOT_SORTED_ARRAY_VISITING_COUNT = 280;
-const REVERSE_SORTED_ARRAY_VISITING_COUNT = 400;
+const NOT_SORTED_ARRAY_VISITING_COUNT = 189;
+const REVERSE_SORTED_ARRAY_VISITING_COUNT = 209;
 const EQUAL_ARRAY_VISITING_COUNT = 20;
 
 describe('BubbleSort', () => {