
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.




using System;
using System.Collections.Generic;
 
namespace RosettaCode.BogoSort
{
    public static class BogoSorter
    {
        public static void Sort<T>(List<T> list) where T:IComparable
        {
            while (!list.isSorted())
            {
                list.Shuffle();
            }
        }
 
        private static bool isSorted<T>(this IList<T> list) where T:IComparable
        {
            if(list.Count<=1)
                return true;
            for (int i = 1 ; i < list.Count; i++)
                if(list[i].CompareTo(list[i-1])<0) return false;
            return true;
        }
 
        private static void Shuffle<T>(this IList<T> list)
        {
            Random rand = new Random();
            for (int i = 0; i < list.Count; i++)
            {
                int swapIndex = rand.Next(list.Count);
                T temp = list[swapIndex];
                list[swapIndex] = list[i];
                list[i] = temp;
            }
        }
    }
 
    class TestProgram
    {
        static void Main()
        {
            List<int> testList = new List<int> { 3, 4, 1, 8, 7, 4, -2 };
            BogoSorter.Sort(testList);
            foreach (int i in testList) Console.Write(i + " ");
        }
 
    }
}