What is the principle of the bubble sort algorithm in the C language?

Bubble sort is a simple sorting algorithm that repeatedly traverses the list to be sorted, compares adjacent elements, and swaps their positions until no more swaps occur. Its basic principle is as follows:

1. Traverse the input array, compare adjacent elements, and swap their positions if the previous element is greater than the next element.
2. Continue iterating through the array, repeating the above comparison and swapping steps, until reaching the last element.
3. After the aforementioned steps are completed, the largest element will be placed in the last position.
4. Repeat the above process, with the number of elements to be sorted decreasing by one each time, until all elements are sorted.

The name “Bubble Sort” comes from the fact that during each traversal, the largest element slowly “bubbles up” to the end of the list. It has a time complexity of O(n^2), where n is the number of elements to be sorted.