Files
JavaScript/Sorts/bubblesort.js
2018-03-30 23:40:08 +02:00

67 lines
1.7 KiB
JavaScript

/*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.
*/
function bubbleSort(items) {
let length = items.length;
for (let i = (length - 1); i > 0; i--) {
//Number of passes
for (let j = (length - i); j > 0; j--) {
//Compare the adjacent positions
if (items[j] < items[j - 1]) {
//Swap the numbers
let tmp = items[j];
items[j] = items[j - 1];
items[j - 1] = tmp;
}
}
}
}
//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);
/*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.
*/
function bubbleSort(arr){
let swapped = true;
while(swapped){
swapped = false;
for(let i = 0; i < arr.length-1; i++){
if(arr[i] > arr[i + 1]){
let temp = arr[i];
arr[i] = arr[i + 1];
arr[i + 1] = temp;
swapped = true;
}
}
}
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(bubbleSort(array));