# Java Program to Implement the Alexander Bogomolny’s UnOrdered Permutation Algorithm for Elements From 1 to N

This is a java program to implement Alexander Bogomolny’s permutation algorithm. This version of program computes all possible permutations of numbers from 1 to N using Alexander Bogomolyn’s algorithm.

Here is the source code of the Java Program to Implement the Alexander Bogomolny’s UnOrdered Permutation Algorithm for Elements From 1 to N. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.

package com.sanfoundry.combinatorial;

import java.util.Scanner;

public class AlexanderBogomolnyPermutation
{
static int level = -1;

public static void print(int[] value, int n)
{
if (value.length != 0)
{
for (int i = 0; i < value.length; i++)
{
System.out.print(value[i] + " ");
}
System.out.println();
}
}

public static void visit(int[] Value, int N, int k)
{
level = level + 1;
Value[k] = level;
if (level == N)
print(Value, N);
else
for (int i = 0; i < N; i++)
if (Value[i] == 0)
visit(Value, N, i);
level = level - 1;
Value[k] = 0;
}

public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
System.out.println("Enter the size of the sequence:");
int n = sc.nextInt();
int sequence[] = new int[n];
for (int i = 0; i < n; i++)
{
sequence[i] = 0;
}
System.out.println("The permutations are: ");
visit(sequence, n, 0);
sc.close();
}
}


Output:

$javac AlexanderBogomolnyPermutation.java$ java AlexanderBogomolnyPermutation

Enter the size of the sequence:
4
The permutations are:
1 2 3 4
1 2 4 3
1 3 2 4
1 4 2 3
1 3 4 2
1 4 3 2
2 1 3 4
2 1 4 3
3 1 2 4
4 1 2 3
3 1 4 2
4 1 3 2
2 3 1 4
2 4 1 3
3 2 1 4
4 2 1 3
3 4 1 2
4 3 1 2
2 3 4 1
2 4 3 1
3 2 4 1
4 2 3 1
3 4 2 1
4 3 2 1