Counting Sort is an sorting algorithm, which sorts the integers( or Objects) given in a specific range.
Algorithm: Time Complexity O(n)
- Take two arrays, Count and Result and given array is input.
- Count will store the counts of each integer in the given array.
- Update the Count so that each index will store the sum till previous step. (Count[i]=Count[i] + Count[i-1]). Now updated Count array will reflect the actual position of each integer in Result.
- Now navigate the input array taking one element at a time, Count[input[i]] will tell you the index position of input[i] in Result. When you do that, decrease the count in Count[input[i]] by 1. See Example
Orginal Array [2, 1, 4, 5, 7, 1, 1, 8, 9, 10, 11, 14, 15, 3, 2, 4] Sorted Array : [0, 1, 1, 1, 2, 2, 3, 4, 4, 5, 7, 8, 9, 10, 11, 14, 15]
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If you find anything incorrect or you feel that there is any better approach to solve the above problem, please write comment.