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This article is to share with you about how to achieve bubble sorting in Python, the editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

Bubble sort (Bubble Sort)

Bubble sorting algorithm: compare and exchange unordered tables multiple times

Each time, the two adjacent elements of the list are compared, and the large ones are put back, so that after all the elements have been compared, the largest item of the current list is placed at the end. Then bubble sort the first 1 data item. Finally, a bubble sort is carried out for one time, and the whole list is sorted (similar to the "bubble" floating process).

1. The first trip of bubbling: a total of nmur1 compare and exchange adjacent data.

two。 The second bubble: the previous nmur1 data items are compared and exchanged, and a total of nmur2 compare and exchange adjacent data items.

……

3. Until the n-1st bubble sort: the smallest item must be at the top of the list

Therefore, a total of 1 bubbling sort will be carried out.

How many trips?

The number of comparisons is the first time nMui 1

The second round

NWhat 2

The third trip

NWhat 3

……

……

The n-1 trip

one

After each bubble sort, there is one less element to be compared. Bubbling sort does not start from 0 times, but from 1 time to 1 time. There are only two elements in the last bubbling, which can be finished directly after comparison and exchange.

Analysis of Bubble sorting algorithm

For bubble sorting, no matter how the data items in the unordered table are arranged, the algorithm process always needs to do one-time bubble sort. With the increase of the number of trips, the number of comparisons decreases from 1 to 1, so the number of comparisons is 1 / 2 / 3 +. + nmur1

(1ax 2) * n ^ 2-(1max 2) * n

Compare time complexity: O (n ^ 2)

Best case of number of exchanges: the number of exchanges is 0 (already sorted)

The worst-case scenario of the number of exchanges: the number of exchanges is nMui 1 (swap for each comparison)

Exchange time complexity: O (n ^ 2)

Therefore, the time complexity of bubble sorting algorithm is O (n ^ 2).

Summary: bubble sorting algorithm is a kind of algorithm with poor time complexity, but it has one advantage-bubble sorting does not take up any extra storage space.

Bubbling sort-- improvement

Although it has been improved, it still does not change its time complexity.

The drawback of bubble sorting performance is that it is compared whether or not it needs to be swapped. In fact, most of the time such a comparison is meaningless.

What does it mean if no exchange takes place in a bubble sort? It means that it has been sorted, and there is no need for the following bubble sorting. On the other hand, as long as there is an exchange, there will be another bubble sort.

The above is how to achieve bubble sorting in Python. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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