Algorithms and Data Structures - Stable Vs. Unstable Sorting Algorithms

Demo

For these examples, we will use two sorting algorithms: Bubble Sort and Selection Sort. The Bubble Sort algorithm is a stable sorting algorithm, while the Selection Sort algorithm is an unstable sorting algorithm. For both algorithms, we will sort a list of people by their age in ascending order. The list of people is shown below.

Algorithms

• Stable Sorting Algorithms
• Unstable Sorting Algorithms

Input

Name	Age	Position
William	21	1
Smith	23	2
Alex	27	3
Paul	21	4
Max	18	5
John	23	6
Bob	25	7
Patrick	21	8
Jane	23	9

Output of stable sorting algorithms

For this example, the stable sorting algorithm is the Bubble Sort algorithm.

Name	Age	Position
Max	18	5
William	21	1
Paul	21	4
Patrick	21	8
Smith	23	2
John	23	6
Jane	23	9
Bob	25	7
Alex	27	3

Output of unstable sorting algorithms

For this example, the unstable sorting algorithm is the Selection Sort algorithm.

Name	Age	Position
Max	18	5
Paul	21	4
William	21	1
Patrick	21	8
John	23	6
Smith	23	2
Jane	23	9
Bob	25	7
Alex	27	3

Conclusion

From the output of the stable sorting algorithm, we can see that the people with the same age are sorted based on their original position in the list. For example, the people with the age of 21 are sorted in the order of their original position in the list.

Name	Age	Position
William	21	1
Paul	21	4
Patrick	21	8

On the other hand, the output of the unstable sorting algorithm shows that the people with the same age are not sorted based on their original position in the list. For example, the people with the age of 21 are not sorted in the order of their original position in the list.

Name	Age	Position
Paul	21	4
William	21	1
Patrick	21	8

References

• Other Algorithms & Data Structures