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

This is a C++ program to implement the Alexander Bogomolny’s UnOrdered Permutation Algorithm for elements from 1 to N

Algorithms

Begin
   function AlexanderBogomolny() to implement the Algorithms
   Arguments:
      Val[] = an array
      N = number of elements taken as input.
      K = level
      Body of the function:
      intialize l = -1
      l = l+1
      Val[k] = l
      if (l == N)
         Call function display(Val, N)
      else
         for i = 0 to N-1
            if (Val[i] == 0)
               Call AlexanderBogomolny(Val, N, i)
            l = l - 1
            Val[k] = 0
End

Example

#include<iostream>
#include<iomanip>
using namespace std;
void display(const int *n, const int size) //to display the permutation
{
   int i;
   if (n != 0) {
      for ( i = 0; i < size; i++) {
         cout<<setw(4)<<n[i];
      }
      cout<<"\n";
   }
}
void AlexanderBogomolny(int *Val, int N, int k) {
   static int l = -1;
   int i;
   //At start,Assign level to 0.
   l = l+1;
   Val[k] = l;
   if (l == N)
      display(Val, N);
   else
      for (i = 0; i < N; i++)
         //Assign values to the array if it is zero.
      if (Val[i] == 0)
         AlexanderBogomolny(Val, N, i);
      //Decrement the level after all possible permutation after that level.
      l = l-1;
      Val[k] = 0;
}
int main() {
   int i, N, cnt = 1;
   cout<<"Enter the value to permute first N natural numbers: ";
   cin>>N;
   int Val[N];
   for (i = 0; i < N; i++) {
      Val[i] = 0;
      cnt *= (i+1);
   }
   cout<<"\nThe number of permutations possible is: "<<cnt;
   cout<<"\n\nPermutation using Alexander Bogomolyn's Algorithms \n";
   AlexanderBogomolny(Val, N, 0);
   return 0;
}

Output

Enter the value to permute first N natural numbers: 5
The number of permutations possible is: 120
Permutation using Alexander Bogomolyn's Algorithms
1 2 3 4 5
1 2 3 5 4
1 2 4 3 5
1 2 5 3 4
1 2 4 5 3
1 2 5 4 3
1 3 2 4 5
1 3 2 5 4
1 4 2 3 5
1 5 2 3 4
1 4 2 5 3
1 5 2 4 3
1 3 4 2 5
1 3 5 2 4
1 4 3 2 5
1 5 3 2 4
1 4 5 2 3
1 5 4 2 3
1 3 4 5 2
1 3 5 4 2
1 4 3 5 2
1 5 3 4 2
1 4 5 3 2
1 5 4 3 2
2 1 3 4 5
2 1 3 5 4
2 1 4 3 5
2 1 5 3 4
2 1 4 5 3
2 1 5 4 3
3 1 2 4 5
3 1 2 5 4
4 1 2 3 5
5 1 2 3 4
4 1 2 5 3
5 1 2 4 3
3 1 4 2 5
3 1 5 2 4
4 1 3 2 5
5 1 3 2 4
4 1 5 2 3
5 1 4 2 3
3 1 4 5 2
3 1 5 4 2
4 1 3 5 2
5 1 3 4 2
4 1 5 3 2
5 1 4 3 2
2 3 1 4 5
2 3 1 5 4
2 4 1 3 5
2 5 1 3 4
2 4 1 5 3
2 5 1 4 3
3 2 1 4 5
3 2 1 5 4
4 2 1 3 5
5 2 1 3 4
4 2 1 5 3
5 2 1 4 3
3 4 1 2 5
3 5 1 2 4
4 3 1 2 5
5 3 1 2 4
4 5 1 2 3
5 4 1 2 3
3 4 1 5 2
3 5 1 4 2
4 3 1 5 2
5 3 1 4 2
4 5 1 3 2
5 4 1 3 2
2 3 4 1 5
2 3 5 1 4
2 4 3 1 5
2 5 3 1 4
2 4 5 1 3
2 5 4 1 3
3 2 4 1 5
3 2 5 1 4
4 2 3 1 5
5 2 3 1 4
4 2 5 1 3
5 2 4 1 3
3 4 2 1 5
3 5 2 1 4
4 3 2 1 5
5 3 2 1 4
4 5 2 1 3
5 4 2 1 3
3 4 5 1 2
3 5 4 1 2
4 3 5 1 2
5 3 4 1 2
4 5 3 1 2
5 4 3 1 2
2 3 4 5 1
2 3 5 4 1
2 4 3 5 1
2 5 3 4 1
2 4 5 3 1
2 5 4 3 1
3 2 4 5 1
3 2 5 4 1
4 2 3 5 1
5 2 3 4 1
4 2 5 3 1
5 2 4 3 1
3 4 2 5 1
3 5 2 4 1
4 3 2 5 1
5 3 2 4 1
4 5 2 3 1
5 4 2 3 1
3 4 5 2 1
3 5 4 2 1
4 3 5 2 1
5 3 4 2 1
4 5 3 2 1
5 4 3 2 1