Thread: Tower of Hanoi Alteration Help!!

I'm having some problem with this problem. It is an alteration to the towers of hanoi problem and I have no idea how to implement it. Here's what I have to do:

The Towers of HaHa problem is the same as the Towers of Hanoi problem. However, the disks are numbered 1 through n; odd-numbered disks are red, and even-numbered ones are yellow. The disks are initially on tower 1 in the order 1 through n from top to bottom. The disks are to be moved to tower 2, and at no time should a disk sit on top of a disk that has the same color. The initial and final disk orders are the same. Write a program to move the disks from tower 1 to tower 2 using tower 3 for intermediate storage. How many disk moves does your program make?

So I started by creating the towers of hanoi problem and I have no idea where to check that they're not the same color when you move them:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <math.h>

#define FROM	1
#define TO	3
#define USING	2

void dohanoi(int N, int from, int to, int using)
{
  if (N > 0) {
    dohanoi(N-1, from, using, to);
	if ((N % 2) == 0) {
		printf ("move Blue %d --> %d\n", from, to);
	} else {
		printf ("move Red %d --> %d\n", from, to);
	}
    dohanoi(N-1, using, to, from);
  }
}

int main (int argc, char **argv)
{
  long int N;

  if (argc != 2) {
    fprintf(stderr, "usage: %s N\n", argv[0]);
    exit(1);
  }

  N = strtol(argv[1], (char **)NULL, 10);

  /* a bit of error checking, LONG_XXX should be there in limits.h */
  if (N == LONG_MIN || N == LONG_MAX || N <= 0) {
    fprintf(stderr, "illegal value for number of disks\n");
    exit(2);
  }

  dohanoi(N, FROM, TO, USING);

  exit(0);
}

Ignore the "color". Just check if they are even or odd.


Quzah.

Well it's not like you have many choices. You have three pegs. You have a source peg, and two destination pegs. If it can't go on one, what's that leave you?


Quzah.

Stop. Go out and buy yourself one of those Fischer-Price pegs with the colored rings. Actually, go buy three of them, and throw two sets of rings away. Then figure out how to play Hanoi with it until you understand what's going on. Until you understand the towers, there's no point in trying to write it. (As you've already been told.)


Quzah.

Code:

int peg1[ MAXRINGS ];
int peg2[ MAXRINGS ];
int peg3[ MAXRINGS ];

Make three pegs, each one is big enough to hold all of your rings. Fill one of them with all the rings in order. Now move them around until they're all in order some place else.


Quzah.

Okay, so I'm on my way. I've initialized the peg1 array based on the number of rings the user inputs. Would it make more sense to use a 2-dimensional array peg[1][maxRings] peg[2][maxRings] peg[3][maxRings]

Code:

#include <stdio.h>  
#include <limits.h>
#include <stdlib.h>


	int peg1[], peg2[], peg3[];	

void hanoi(int n,int from,int using,int to) {
	
	
	if (n==1)
	{
		printf("Move from %d to %d.\n",from,to);
	} else {
		
		hanoi(n-1,from,to,using);
		hanoi(1,from,using,to);
		hanoi(n-1,to,using,from);
	} 
} 

int main(int argc, char **argv) { 
	int maxRings = strtol(argv[1], (char **)NULL, 10);
	int i, j, peg1[maxRings], peg2[maxRings], peg3[maxRings];
	
	for (j = 0; j < maxRings; j++) {
		for (i = maxRings-j; i>0; i--) {
			peg1[j] = i;
			break;
		}
	}
	hanoi(4,1,3,2); 
	exit(0);
}