Java Program for BogoSort or Permutation Sort

BogoSort also known as permutation sort, stupid sort, slow sort, shotgun sort or monkey sort is a particularly ineffective algorithm based on generate and test paradigm. The algorithm successively generates permutations of its input until it finds one that is sorted.(Wiki)
For example, if bogosort is used to sort a deck of cards, it would consist of checking if the deck were in order, and if it were not, one would throw the deck into the air, pick the cards up at random, and repeat the process until the deck is sorted.

PseudoCode:

while not Sorted(list) do
    shuffle (list)
done
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// Java Program to implement BogoSort
public class BogoSort {
    // Sorts array a[0..n-1] using Bogo sort
    void bogoSort(int[] a)
    {
        // if array is not sorted then shuffle the
        // array again
        while (isSorted(a) == false)
            shuffle(a);
    }
  
    // To generate permuatation of the array
    void shuffle(int[] a)
    {
        // Math.random() returns a double positive
        // value, greater than or equal to 0.0 and
        // less than 1.0.
        for (int i = 0; i < a.length; i++)
            swap(a, i, (int)(Math.random() * i));
    }
  
    // Swapping 2 elements
    void swap(int[] a, int i, int j)
    {
        int temp = a[i];
        a[i] = a[j];
        a[j] = temp;
    }
  
    // To check if array is sorted or not
    boolean isSorted(int[] a)
    {
        for (int i = 1; i < a.length; i++)
            if (a[i] < a[i - 1])
                return false;
        return true;
    }
  
    // Prints the array
    void printArray(int[] arr)
    {
        for (int i = 0; i < arr.length; i++)
            System.out.print(arr[i] + " ");
        System.out.println();
    }
  
    public static void main(String[] args)
    {
        // Enter array to be sorted here
        int[] a = { 3, 2, 5, 1, 0, 4 };
        BogoSort ob = new BogoSort();
  
        ob.bogoSort(a);
  
        System.out.print("Sorted array: ");
        ob.printArray(a);
    }
}

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Output:

Sorted array: 0 1 2 3 4 5

Please refer complete article on BogoSort or Permutation Sort for more details!

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