Radix sort

In computer science, radix sort is a non-comparative sorting algorithm. It avoids comparison by creating and distributing elements into buckets according to their radix. For elements with more than one significant digit, this bucketing process is repeated for each digit, while preserving the ordering of the prior step, until all digits have been considered. For this reason, radix sort has also been called bucket sort and digital sort.

Radix sort

Class	Sorting algorithm
Data structure	Array
Worst-case performance	${\displaystyle O(w\cdot n)}$, where ${\displaystyle n}$ is the number of keys, and ${\displaystyle w}$ is the key length.
Worst-case space complexity	${\displaystyle O(w+n)}$
Optimal	exactly correct

Radix sort can be applied to data that can be sorted lexicographically, be they integers, words, punch cards, playing cards, or the mail.