
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

Bogosort a list of numbers.



Bogosort simply shuffles a collection randomly until it is sorted.

"Bogosort" is a perversely inefficient algorithm only used as an in-joke.

Its average run-time is   O(n!)   because the chance that any given shuffle of a set will end up in sorted order is about one in   n   factorial,   and the worst case is infinite since there's no guarantee that a random shuffling will ever produce a sorted sequence.

Its best case is   O(n)   since a single pass through the elements may suffice to order them.



Pseudocode:

while not InOrder(list) do
   Shuffle(list)
done



The Knuth shuffle may be used to implement the shuffle part of this algorithm.




// version 1.1.2
 
const val RAND_MAX = 32768 // big enough for this
 
val rand = java.util.Random()
 
fun isSorted(a: IntArray): Boolean {
    val n = a.size
    if (n < 2) return true
    for (i in 1 until n) {
        if (a[i] < a[i - 1]) return false
    }
    return true
}
 
fun shuffle(a: IntArray) {
    val n = a.size
    if (n < 2) return
    for (i in 0 until n) {
        val t = a[i]
        val r = rand.nextInt(RAND_MAX) % n
        a[i] = a[r]
        a[r] = t
    }
}
 
fun bogosort(a: IntArray) {
   while (!isSorted(a)) shuffle(a)
}
 
fun main(args: Array<String>) {
    val a = intArrayOf(1, 10, 9,  7, 3, 0)
    println("Before sorting : ${a.contentToString()}")
    bogosort(a)
    println("After sorting  : ${a.contentToString()}")
}