Bubble Sort

Overview

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements, and swaps them if they are in the wrong order. The algorithm gets its name because smaller elements "bubble" to the top of the list like bubbles in water.

How Bubble Sort Works

The algorithm makes multiple passes through the array. In each pass, it compares each pair of adjacent elements and swaps them if the first is greater than the second. After each complete pass, the largest unsorted element has "bubbled" to its correct position at the end.

The Sorting Process

After the first pass, the largest element is at the end. After the second pass, the second largest is in the second-to-last position, and so on. The process continues until no swaps are needed in a complete pass, indicating the array is sorted.

Time Complexity

Bubble sort has O(n²) time complexity in both average and worst cases, making it inefficient for large datasets. In the best case of an already sorted array, it can be optimized to O(n) by detecting when no swaps occur.

Why Learn Bubble Sort

Despite its inefficiency, bubble sort is valuable for learning sorting concepts because it's simple to understand and implement. It helps build intuition about comparison-based sorting and provides a foundation for understanding more advanced algorithms.

When Not to Use It

Bubble sort should not be used for real-world applications with large datasets. Modern sorting algorithms like quicksort or mergesort are much faster. However, its simplicity makes it useful for educational purposes and very small datasets.