bubble-sort.js

// bubble-sort.js — Bubble sort algorithm with visualization step tracking
// Extracted from sortingAlgorithms.js for single-responsibility.

/**
 * Bubble sort — compares adjacent elements and swaps if out of order.
 * Returns an array of step objects for animation.
 * @param {Array} arr - Array of {width, ...} objects to sort
 * @returns {Array} Array of {xx, yy, changed} step objects
 */
export function bubbleSort(arr){
    const pairs= [];
    let n = arr.length;
    const prevRect = arr.slice();
    for (let i = 0; i < n-1; i++){
        for (let j = 0; j < n-i-1; j++){
            if (prevRect[j].width > prevRect[j+1].width) {
                // swap arr[j+1] and arr[j]
                const recti = {...prevRect[j]};
                const rectj = {...prevRect[j+1]};
                prevRect[j+1] = recti;
                prevRect[j] = rectj;
                pairs.push( {
                    xx:j,
                    yy:j+1,
                    changed:true
                } );
            } else{
                pairs.push( {
                    xx:j,
                    yy:j+1,
                    changed:false
                } );
            }
            if( j === n-i-2 ){
                pairs.push( {
                    xx:n-i-1,
                    yy:n-i-1,
                    changed:false
                } );
            }
        }
    }
    pairs.push({
            xx:0,
            yy:0,
            changed:false
        }
    )
    return pairs;
}