
Sorting Algorithm

This is a sorting algorithm.   It may be applied to a set of data in order to sort it.    
For comparing various sorts, see compare sorts.  
For other sorting algorithms,   see sorting algorithms,   or:

O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
O(n2) sorts
Bubble sort |
Cocktail sort |
Cocktail sort with shifting bounds |
Comb sort |
Cycle sort |
Gnome sort |
Insertion sort |
Selection sort |
Strand sort
other sorts
Bead sort |
Bogo sort |
Common sorted list |
Composite structures sort |
Custom comparator sort |
Counting sort |
Disjoint sublist sort |
External sort |
Jort sort |
Lexicographical sort |
Natural sorting |
Order by pair comparisons |
Order disjoint list items |
Order two numerical lists |
Object identifier (OID) sort |
Pancake sort |
Quickselect |
Permutation sort |
Radix sort |
Ranking methods |
Remove duplicate elements |
Sleep sort |
Stooge sort |
[Sort letters of a string] |
Three variable sort |
Topological sort |
Tree sort


Task

Sort an array of positive integers using the Bead Sort Algorithm.

A   bead sort   is also known as a   gravity sort.



Algorithm has   O(S),   where   S   is the sum of the integers in the input set:   Each bead is moved individually.

This is the case when bead sort is implemented without a mechanism to assist in finding empty spaces below the beads, such as in software implementations.




// version 1.1.2
 
fun beadSort(a: IntArray) {
    val n = a.size
    if (n < 2) return
    var max = a.max()!!
    val beads = ByteArray(max * n)
    /* mark the beads */
    for (i in 0 until n)
        for (j in 0 until a[i])
            beads[i * max + j] = 1
 
    for (j in 0 until max) {
        /* count how many beads are on each post */
        var sum = 0
        for (i in 0 until n) {
            sum += beads[i * max + j]
            beads[i * max + j] = 0
        }
        /* mark bottom sum beads */
        for (i in n - sum until n) beads[i * max + j] = 1
    }
 
    for (i in 0 until n) {
        var j = 0
        while (j < max && beads[i * max + j] == 1.toByte()) j++
        a[i] = j
    }
}
 
fun main(args: Array<String>) {
    val a  = intArrayOf(5, 3, 1, 7, 4, 1, 1, 20)
    println("Before sorting : ${a.contentToString()}")
    beadSort(a)
    println("After sorting  : ${a.contentToString()}")
}