sorting programs

sortings

let arrayToBeSort = [12,45,75,35,55,54,2,21]

// ## Bubble Sort
/**
 * 
 * Bubble sort is a simple sorting algorithm.
 * This sorting algorithm is comparison-based algorithm
 * in which each pair of adjacent elements is compared 
 * and the elements are swapped if they are not in order.
 * This algorithm is not suitable for large data sets as
 * its average and worst case complexity are of Ο(n2)
 * where n is the number of items. 
 */
function bubbleSort(arrayToBeSort){
    // take the length of array
    let arrayLength = arrayToBeSort.length
    for(let i = 1; i <= arrayLength; i++){
        for(let j = 0; j < arrayLength - i ; j++){
            if(arrayToBeSort[j] > arrayToBeSort[j+1]){
                let temp = arrayToBeSort[j]
                arrayToBeSort[j] = arrayToBeSort[j+1]
                arrayToBeSort[j+1] = temp
            }
        }
    }
}

// ## Insertion Sort
/**
 * 
 * This is an in-place comparison-based sorting algorithm. Here,
 *  a sub-list is maintained which is always sorted. For example,
 *  the lower part of an array is maintained to be sorted.
 *  An element which is to be 'insert'ed in this sorted sub-list, 
 * has to find its appropriate place and then it has to be inserted there. Hence the name, insertion sort.
 * The array is searched sequentially and unsorted items are moved and inserted into the sorted sub-list (in the same array).
 * This algorithm is not suitable for large data sets as its average and worst case complexity are of Ο(n2), 
 * where n is the number of items.
 */
function insertionSort(arrayToBeSort){
    let arrayLength = arrayToBeSort.length
    for(let i = 0; i < arrayLength; i++){
        for(let j = i; j > 0; j --){
            if(arrayToBeSort[j-1] > arrayToBeSort[j]){
                let temp = arrayToBeSort[j-1]
                arrayToBeSort[j-1] = arrayToBeSort[j]
                arrayToBeSort[j] = temp
            }
            else
                break;
        }
    }
}

//## 
/**
 * 
 * Selection sort is a simple sorting algorithm.
 *  This sorting algorithm is an in-place comparison-based algorithm
 *  in which the list is divided into two parts, the sorted part at 
 * the left end and the unsorted part at the right end. Initially, 
 * the sorted part is empty and the unsorted part is the entire list.
 * 
 * The smallest element is selected from the unsorted array and swapped
 *  with the leftmost element, and that element becomes a part of the sorted array.
 *  Thisprocess continues moving unsorted array boundary by one element to the right.
 * 
 * This algorithm is not suitable for large data sets as its average and worst case
 * complexities are of Ο(n2), where n is the number of items.
 */

function selectionSort(arrayToBeSort){
    let arrayLength = arrayToBeSort.length
    for(let i = 0; i < arrayLength -1; i++){
        let minIndex = i;
        for(let j = minIndex + 1; j < arrayLength; j++ ){
            if(arrayToBeSort[minIndex] > arrayToBeSort[j])
                minIndex = j
        }
        if(minIndex !== i){
            let temp = arrayToBeSort[i]
            arrayToBeSort[i] = arrayToBeSort[minIndex]
            arrayToBeSort[minIndex] = temp
        }
    }
}