Question

I have a recursive Tower of Hanoi program but don't know how to include the count variable. Could you tell me how?

Main.java

import java.io.*;

import java.util.List;

public class Main {

//int count = 0;

/**There is a stack of N disks on the first of three poles (call

them A, B and C) and your job is to move the disks from pole A to pole B without

ever putting a larger disk on top of a smaller disk.*/

public static void main(String[] args) {

System.out.println("Tower of Hanoi");

System.out.println("Program by Quang Pham");

playHanoi (3,"A","B","C");

System.out.println("All done.");

System.out.println("Took a total of n" + /*count*/ " moves.");

}

//move n disks from position "from" to "to" via "other"

private static void playHanoi( int n, String from , String other, String to) {

if (n == 0)

return;

if (n > 0)

playHanoi(n-1, from, to, other);

System.out.printf(/*"%d." +*/ "Move disk" + n + "from pole %s to pole %s \n ", /*count*/ from, to);

playHanoi(n-1, other, from, to);

}

/*int count++;*/

}

Any help with this problem would be greatly appreciated. Yours truly, Quang Pham

Answer 1

The code above has been modified to give the count for the Tower of hanoi problem.

import java.io.*;

import java.util.List;

public class Main {

public static void main(String[] args) {

int count=playHanoi (3,"A","B","C");

System.out.println("Took a total of n" + count+ " moves.");

}

private static int playHanoi( int n, String from , String other, String to)

{ int count=1;

if (n == 0)

return;

else if(n==1)

{

System.out.println("move disk "+n+" from rod "+from+" to rod "+to);
        return count;

}

else{

count+= playHanoi(n-1, from, to, other);

System.out.printf(/*"%d." +*/ "Move disk" + n + "from pole %s to pole %s \n ", /*count*/ from, to);

count+=playHanoi(n-1, other, from, to);

}

return count;

}

}