Pigeonhole sort

Pigeonhole sort
Class	Sorting algorithm
Data structure	Array
Worst-case performance	[math]\displaystyle{ O(N+n) }[/math], where N is the range of key values and n is the input size
Worst-case space complexity	[math]\displaystyle{ O(N+n) }[/math]

Pigeonhole sorting is a sorting algorithm that is suitable for sorting lists of elements where the number n of elements and the length N of the range of possible key values are approximately the same.^[1] It requires O(n + N) time. It is similar to counting sort, but differs in that it "moves items twice: once to the bucket array and again to the final destination [whereas] counting sort builds an auxiliary array then uses the array to compute each item's final destination and move the item there."^[2]

The pigeonhole algorithm works as follows:

Given an array of values to be sorted, set up an auxiliary array of initially empty "pigeonholes", one pigeonhole for each key in the range of the keys in the original array.
Going over the original array, put each value into the pigeonhole corresponding to its key, such that each pigeonhole eventually contains a list of all values with that key.
Iterate over the pigeonhole array in increasing order of keys, and for each pigeonhole, put its elements into the original array in increasing order.

References

ru:Сортировка подсчётом#Алгоритм со списком

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Pigeonhole sort. Read more

[1] "NIST's Dictionary of Algorithms and Data Structures: pigeonhole sort". https://xlinux.nist.gov/dads/HTML/pigeonholeSort.html.

[2] Black, Paul E.. "Dictionary of Algorithms and Data Structures". https://xlinux.nist.gov/dads/HTML/pigeonholeSort.html.

[1]

[2]

v t e Sorting algorithms
Theory	Computational complexity theory Big O notation Total order Lists Inplacement Stability Comparison sort Adaptive sort Sorting network Integer sorting X + Y sorting Transdichotomous model Quantum sort
Exchange sorts	Bubble sort Cocktail shaker sort Odd–even sort Comb sort Gnome sort Quicksort Slowsort Stooge sort Bogosort
Selection sorts	Selection sort Heapsort Smoothsort Cartesian tree sort Tournament sort Cycle sort Weak-heap sort
Insertion sorts	Insertion sort Shellsort Splaysort Tree sort Library sort Patience sorting
Merge sorts	Merge sort Cascade merge sort Oscillating merge sort Polyphase merge sort
Distribution sorts	American flag sort Bead sort Bucket sort Burstsort Counting sort Interpolation sort Pigeonhole sort Proxmap sort Radix sort Flashsort
Concurrent sorts	Bitonic sorter Batcher odd–even mergesort Pairwise sorting network
Hybrid sorts	Block merge sort Timsort Introsort Spreadsort Merge-insertion sort
Other	Topological sorting Pre-topological order Pancake sorting Spaghetti sort

Pigeonhole sort

See also

References