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def bubble_sort(collection):
    """Pure implementation of bubble sort algorithm in Python

    :param collection: some mutable ordered collection with heterogeneous
    comparable items inside
    :return: the same collection ordered by ascending

    Examples:
    >>> bubble_sort([0, 5, 2, 3, 2])
    [0, 2, 2, 3, 5]
    >>> bubble_sort([0, 5, 2, 3, 2]) == sorted([0, 5, 2, 3, 2])
    True
    >>> bubble_sort([]) == sorted([])
    True
    >>> bubble_sort([-2, -45, -5]) == sorted([-2, -45, -5])
    True
    >>> bubble_sort([-23, 0, 6, -4, 34]) == sorted([-23, 0, 6, -4, 34])
    True
    >>> bubble_sort(['d', 'a', 'b', 'e', 'c']) == sorted(['d', 'a', 'b', 'e', 'c'])
    True
    >>> import random
    >>> collection = random.sample(range(-50, 50), 100)
    >>> bubble_sort(collection) == sorted(collection)
    True
    >>> import string
    >>> collection = random.choices(string.ascii_letters + string.digits, k=100)
    >>> bubble_sort(collection) == sorted(collection)
    True
    """
    length = len(collection)
    for i in range(length - 1):
        swapped = False
        for j in range(length - 1 - i):
            if collection[j] > collection[j + 1]:
                swapped = True
                collection[j], collection[j + 1] = collection[j + 1], collection[j]
        if not swapped:
            break  # Stop iteration if the collection is sorted.
    return collection


if __name__ == "__main__":
    import doctest
    import time

    doctest.testmod()

    user_input = input("Enter numbers separated by a comma:").strip()
    unsorted = [int(item) for item in user_input.split(",")]
    start = time.process_time()
    print(*bubble_sort(unsorted), sep=",")
    print(f"Processing time: {time.process_time() - start}")

Bubble Sort

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Problem Statement

Given an unsorted array of n elements, write a function to sort the array

Approach

  • select the first element of the array
  • compare it with its next element
  • if it is larger than the next element then swap them
  • else do nothing
  • keep doing this for every index of the array
  • repeat the above process n times.

Time Complexity

O(n^2) Worst case performance

O(n) Best-case performance

O(n^2) Average performance

Space Complexity

O(1) Worst case

Founder's Name

  • The term “Bubble Sort” was first used by Iverson, K in 1962.

Example

arr[] = {10, 80, 40, 30}
Indexes: 0   1   2   3    

1. Index = 0, Number = 10
2. 10 < 80, do nothing and continue

3. Index = 1, Number = 80
4. 80 > 40, swap 80 and 40
5. The array now is {10, 40, 80, 30}

6. Index = 2, Number = 80
7. 80 > 30, swap 80 and 30
8. The array now is {10, 40, 30, 80}

Repeat the Above Steps again

arr[] = {10, 40, 30, 80}
Indexes: 0   1   2   3   

1. Index = 0, Number = 10
2. 10 < 40, do nothing and continue

3. Index = 1, Number = 40
4. 40 > 30, swap 40 and 30
5. The array now is {10, 30, 40, 80}

6. Index = 2, Number = 40
7. 40 < 80, do nothing
8. The array now is {10, 30, 40, 80}

Repeat the Above Steps again

arr[] = {10, 30, 40, 80}
Indexes: 0   1   2   3   

1. Index = 0, Number = 10
2. 10 < 30, do nothing and continue

3. Index = 1, Number = 30
4. 30 < 40, do nothing and continue

5. Index = 2, Number = 40
6. 40 < 80, do nothing

Since there are no swaps in above steps, it means the array is sorted and we can stop here.

Code Implementation Links

Video Explanation

A video explaining the Bubble Sort Algorithm

Others

Bubble sort is also known as Sinking sort.

Animation Explanation