How to use method for solving Tower of Hanoi problem in Java

Problem Description

How to use method for solving Tower of Hanoi problem?

Solution

This example displays the way of using method for solving Tower of Hanoi problem( for 3 disks).

public class MainClass {
   public static void main(String[] args) {
      int nDisks = 3;
      doTowers(nDisks, 'A', 'B', 'C');
   }
   public static void doTowers(int topN, char from, char inter, char to) {
      if (topN == 1) {
         System.out.println("Disk 1 from " + from + " to " + to);
      } else {
         doTowers(topN - 1, from, to, inter);
         System.out.println("Disk " + topN + " from " + from + " to " + to);
         doTowers(topN - 1, inter, from, to);
      }
   }
}

Result

The above code sample will produce the following result.

Disk 1 from A to C
Disk 2 from A to B
Disk 1 from C to B
Disk 3 from A to C
Disk 1 from B to A
Disk 2 from B to C
Disk 1 from A to C

The following is an another sample example of Tower of Hanoi

public class TowersOfHanoi {
   public static void move(int n, int startPole, int endPole) {
      if (n == 0) {
         return;
      } 
      int intermediatePole = 6 - startPole - endPole;
      move(n-1, startPole, intermediatePole);
      System.out.println("Move " +n + " from " + startPole + " to " +endPole);
      move(n-1, intermediatePole, endPole);
   } 
   public static void main(String[] args) {
      move(5, 1, 3);
   }
}

The above code sample will produce the following result.

Move 1 from 1 to 3
Move 2 from 1 to 2
Move 1 from 3 to 2
Move 3 from 1 to 3
Move 1 from 2 to 1
Move 2 from 2 to 3
Move 1 from 1 to 3
Move 4 from 1 to 2
Move 1 from 3 to 2
Move 2 from 3 to 1
Move 1 from 2 to 1
Move 3 from 3 to 2
Move 1 from 1 to 3
Move 2 from 1 to 2
Move 1 from 3 to 2
Move 5 from 1 to 3
Move 1 from 2 to 1
Move 2 from 2 to 3
Move 1 from 1 to 3
Move 3 from 2 to 1
Move 1 from 3 to 2
Move 2 from 3 to 1
Move 1 from 2 to 1
Move 4 from 2 to 3
Move 1 from 1 to 3
Move 2 from 1 to 2
Move 1 from 3 to 2
Move 3 from 1 to 3
Move 1 from 2 to 1
Move 2 from 2 to 3
Move 1 from 1 to 3