Stable sorting algorithms

Question

Show that any comparison based sorting algorithm can be made stable without increasing its complexity beyond a constant factor.

Comments

Don't swap when numbers are equal ...is nt that the idea ?

Answer 1

Any given sorting algo which is not stable can be modified to be stable. There can be sorting algo specific ways to make it stable, but in general, any comparison based sorting algorithm which is not stable by nature can be modified to be stable by changing the key comparison operation so that the comparison of two keys considers position as a factor for objects with equal keys.

Key comparison operation is always satisfies transitivity property. So, complexity of stable sort shouldnot increase more than a constant factor.

http://www.geeksforgeeks.org/stability-in-sorting-algorithms/

https://en.wikipedia.org/wiki/Sorting_algorithm#Stability

https://en.wikipedia.org/wiki/Comparison_sort

Comments

Plz correct me if wrong

Answer 2

https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-046j-introduction-to-algorithms-sma-5503-fall-2005/exams/prac_quiz1sol.pdf

Problem 3