sortint

Sortint is a term used in computer science to describe a class of sorting methods that exploit the discrete nature of integers to achieve faster performance than generic comparison-based sorts. The concept focuses on sorting integer keys, often when the value range is known and limited. In practice, sortint implementations appear in library routines and educational materials as an alternative to traditional O(n log n) sorts for suitable data sets.

Many sortint techniques, most notably counting sort, radix sort, and bucket sort, rely on the range and distribution of input values rather than pairwise comparisons. They typically require that keys be integers within a bounded range, and they may require additional memory proportional to the range or the number of digits. Handling negative integers usually involves offsetting or sign-aware partitions.

Counting sort processes each key value by tallying frequencies, yielding O(n + k) time and O(k) space, where k is the maximum key. Radix sort sorts on digit or bit significance in multiple passes, achieving near-linear time for numbers with a bounded digit length, and can run in O(n) time with suitable word size. Bucket sort distributes elements into buckets and then sorts within buckets.

Sortint methods often produce stable results, preserving input order of equal keys, though stability is not universal. They excel when the key domain is small relative to the number of items and when random access memory is abundant; they are less attractive if k is enormous or the data includes many non-integer fields without a straightforward projection.

See also: counting sort, radix sort, bucket sort, general-purpose sorting.