algolibrary/sortLib/bubbleSort.js

A collection of efficient algorithms

/**
 * author: Gowru Sree Vathsa
 * Created on: 28th Dec 2024
 * Last modified on: 28th Dec 2024
 */



/**
 * Bubble Sort implementation.
 * 
 * This function sorts an array of numbers using the bubble sort algorithm.
 * 
 * **Time Complexity:**
 *   - Best Case: O(n) (when the array is already sorted)
 *   - Average Case: O(n^2)
 *   - Worst Case: O(n^2) (when the array is sorted in reverse order)
 *
 * **Space Complexity:** O(1) (in-place sorting)
 * 
 * @param {number[]} arr - The array of numbers to be sorted.
 * @param {number} desc - Flag to determine sorting order. 
 *                        0 (default): Ascending order. 
 *                        Any other value: Descending order.
 * @returns {number[]} - The sorted array.
 */

function sort(arr, sortBy){
    if(sortBy instanceof Function){
        return bubbleSortWithCompare(arr, sortBy);
    }
    else if(typeof sortBy === "number"){
        return bubbleSort(arr, sortBy);
    }
}

function bubbleSort(arr, desc = 0){

    // Check if the input is an array.
    if(!Array.isArray(arr)){
        throw new Error("Invalid input. Expected an array.");
    }

    // Check if the array is empty.
    if(arr.length === 0){
        return arr;
    }

    // Sort based on the provided flag.
    if(desc == 0){
        return bubbleSortAsc(arr);
    }
    else{
        return bubbleSortDesc(arr);
    }
}


function bubbleSortWithCompare(arr, compareFn = (a, b) => a > b){
    let len = arr.length;
    let swapped;

    do{
        swapped = false;
        for(let i = 0; i<len-1; ++i){
            // Compare adjacent elements and swap them if they are in the wrong order.
            if(compareFn(arr[i], arr[i+1])){
                [arr[i], arr[i+1]] = [arr[i+1], arr[i]];
                swapped = true;
            }
        }
        --len;
    } while(swapped);

    return arr;
}


function bubbleSortAsc(arr){
    let len = arr.length;
    let swapped;

    do{
        swapped = false;
        for(let i = 0; i<len-1; ++i){
            // Compare adjacent elements and swap them if they are in the wrong order.
            if(arr[i] > arr[i+1]){
                [arr[i], arr[i+1]] = [arr[i+1], arr[i]];
                swapped = true;
            }
        }
        --len;
    } while(swapped);

    return arr;
}

function bubbleSortDesc(arr){
    let len = arr.length;
    let swapped;

    do{
        swapped = false;
        for(let i = 0; i<len-1; ++i){
            // Compare adjacent elements and swap them if they are in the wrong order.
            if(arr[i] < arr[i+1]){
                [arr[i], arr[i+1]] = [arr[i+1], arr[i]];
                swapped = true;
            }
        }
        --len;
    } while(swapped);

    return arr;
}

module.exports = {
    sort
};