Sorting algorithm

Summary

A sorting algorithm is an algorithm that rearranges a finite list of elements of a totally ordered set into nondecreasing order. Sorting is one of the most studied problems of computer science, because sorted data makes searching, merging and many other tasks fast. Algorithms are compared by their number of comparisons, their memory use and whether they are stable. Every comparison-based sorting algorithm needs about $n \log_2 n$ comparisons in the worst case, by the comparison sort lower bound.