Thread: Towers of Hanoi is making my head explode and also overflowing badly

I am so confused. Input # of disks, start peg and end peg. My program is failing miserably yet it is pretty much the exact code that supposedly works. The function keeps subtracting one until it goes haywire. Please see the program and output below. Any help would be appreciated. Thank you in advance.

Code:

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


// Function Prototypes
void SolveTower(unsigned d, unsigned from, unsigned to, unsigned aux);


// Main Program
int main()
{
    unsigned disks, pegstart, pegend;
    printf("How many disks do you want to move?");
    scanf_s("%u", &disks);
    printf("     From which peg? [1 - 3] --> ");
    scanf_s("%u", &pegstart);
    printf("       To which peg? [1 - 3] --> ");
    scanf_s("%u", &pegend);
    printf("\n======= The Tower of Hanoi Solution ========\n");
    SolveTower(disks, pegstart, pegend, 6 - pegstart - pegend);
    printf("\n============================================\n");
}


// Function Definitions
void SolveTower(unsigned d, unsigned from, unsigned to, unsigned aux)
{
    if (d == 1)
        printf("\nMove a disk from peg %u to peg %u.", from, to);
    else
        printf("\nDisks=%u; From=%u; To=%u; Aux=%u\n", d, from, to, aux); system("pause");  // Debugging code only
        SolveTower(d - 1, from, aux, to);
        printf("\n(ELSE MOVE) Move a disk from peg %u to peg %u.", from, to);
        SolveTower(d - 1, aux, to, from);
}

Output:
How many disks do you want to move?4
From which peg? [1 - 3] --> 1
To which peg? [1 - 3] --> 3


======= The Tower of Hanoi Solution ========


Disks=4; From=1; To=3; Aux=2
Press any key to continue . . .


Disks=3; From=1; To=2; Aux=3
Press any key to continue . . .


Disks=2; From=1; To=3; Aux=2
Press any key to continue . . .


Move a disk from peg 1 to peg 2.Press any key to continue . . .


Disks=0; From=1; To=3; Aux=2
Press any key to continue . . .

Disks=4294967295; From=1; To=2; Aux=3
Press any key to continue . . .

Disks=4294967294; From=1; To=3; Aux=2
Press any key to continue . . .

Hurry I need to finish this so I can release it virally on December 21, 2012. All will be well with the universe I promise. =)

I'm embarrassed. I didn't have brackets around my else statement so it was blowing up. All is well in the universe again. =)

Glad you got it sorted out. You should look into using an editor that has an "auto-indent" feature. If you had a decent one (and there are many free, decent editors out there), it would very likely have made the indentation reflect the flow of the program, i.e. the two recursive calls to SolveTower, and the printf between them, line up with the if and else lines, so you could see that something was wrong.

EDIT: oh, and don't be embarrassed. Everybody has made that mistake a number of times.