JavaAlgorithms/Sorts/BogoSort.java

package Sorts;

import java.util.Random;

/**
 * @author Podshivalov Nikita (https://github.com/nikitap492)
 * @see SortAlgorithm
 */
public class BogoSort implements SortAlgorithm {

  private static final Random random = new Random();

  private static <T extends Comparable<T>> boolean isSorted(T[] array) {
    for (int i = 0; i < array.length - 1; i++) {
      if (SortUtils.less(array[i + 1], array[i])) return false;
    }
    return true;
  }

  // Randomly shuffles the array
  private static <T> void nextPermutation(T[] array) {
    int length = array.length;

    for (int i = 0; i < array.length; i++) {
      int randomIndex = i + random.nextInt(length - i);
      SortUtils.swap(array, randomIndex, i);
    }
  }

  public <T extends Comparable<T>> T[] sort(T[] array) {
    while (!isSorted(array)) {
      nextPermutation(array);
    }
    return array;
  }

  // Driver Program
  public static void main(String[] args) {
    // Integer Input
    Integer[] integers = {4, 23, 6, 78, 1, 54, 231, 9, 12};

    BogoSort bogoSort = new BogoSort();

    // print a sorted array
    SortUtils.print(bogoSort.sort(integers));

    // String Input
    String[] strings = {"c", "a", "e", "b", "d"};

    SortUtils.print(bogoSort.sort(strings));
  }
}