Iterative Tower of Hanoi

import java.util.*;
import java.lang.*;
import java.io.*;
public class TowerOfHanoi{
	
// Stack Class
class Stack
{
	int capacity;
	int top;
	int array[];
}

// This function will create a new stack of the given capacity
Stack initStack(int capacity)
{
	Stack st = new Stack();
	st.capacity = capacity;
	st.top = -1;
	st.array = new int[capacity];
	return st;
}

// This function checks whether the stack is full or not
boolean isFull(Stack st)
{
	return (st.top == st.capacity - 1);
}

// This function checks whether the stack is empty or not
boolean isEmpty(Stack st)
{
	return (st.top == -1);
}

// This function adds this item to the stack.
void push(Stack st, int item)
{
	if (isFull(st)) {
		return;
	}
		
	st.array[++st.top] = item;
}

// This function removes the top of the stack.
int pop(Stack st)
{
	if (isEmpty(st))
		return Integer.MIN_VALUE;
		
	return st.array[st.top--];
}

// This function carries out the movement of the disk between two poles.
void move(Stack src, Stack dest,
							char s, char d)
{
	int disk1 = pop(src);
	int disk2 = pop(dest);

	// Is rod 1 is empty
	if (disk1 == Integer.MIN_VALUE)
	{
		push(src, disk2);
		printMove(d, s, disk2);
	}
	
	// if rod 2  is empty
	else if (disk2 == Integer.MIN_VALUE)
	{
		push(dest, disk1);
		printMove(s, d, disk1);
	}
	
	// If Disk 1 > Disk 2
	else if (disk1 > disk2)
	{
		push(src, disk1);
		push(src, disk2);
		printMove(d, s, disk2);
	}
	// If Disk 1 < Disk 2
	else
	{
		push(dest, disk2);
		push(dest, disk1);
		printMove(s, d, disk1);
	}
}

// This function will print the movement of disks
void printMove(char from, char to, int disk)
{
	System.out.println("Move the disk " + disk +
							" from " + from +
							" to " + to);
}

// Function to implement the algorithm
void iterativeTowerOfHanoi(int n, Stack
				src, Stack aux, Stack dest)
{
	int i, moves;
	char s = 'S', d = 'D', a = 'A';

    // If n is even then exchange the position of destination rod and auxiliary rod.
	if (n % 2 == 0)
	{
		char temp = d;
		d = a;
		a = temp;
	}
	moves = (int)(Math.pow(
						2, n) - 1);

	for(i = n; i >= 1; i--)
		push(src, i);

	for(i = 1; i <= moves; i++)
	{
		if (i % 3 == 1)
		move(src, dest, s, d);

		else if (i % 3 == 2)
		move(src, aux, s, a);

		else if (i % 3 == 0)
		move(aux, dest, a, d);
	}
}

    // Main function
    public static void main(String[] args)
    {
	
	int n = 3;
	
	TowerOfHanoi ob = new TowerOfHanoi();

	// Create three stacks (Source, destination, Auxiliary)
	Stack source = ob.initStack(n);
	Stack destination = ob.initStack(n);
      Stack auxiliary = ob.initStack(n);
	
	ob.iterativeTowerOfHanoi(n, source, auxiliary, destination);
    }
}