hanoi.c - Hele programmet.

Lektion 8 - slide 21 : 27 Program 1

#include <stdio.h>

enum tower {left, middle, right};
typedef enum tower tower;

void move_one_disc(tower a, tower b);
char *tower_out(tower t);


/* Move n discs from tower a to tower b via tower c */
void hanoi(int n, tower a, tower b, tower c){
  if (n == 1)
    move_one_disc(a,b);
  else {
    hanoi(n-1,a,c,b);
    move_one_disc(a,b);
    hanoi(n-1,c,b,a);    
  }
}  

void move_one_disc(tower a, tower b){
  static long count = 0;
  count++;
  printf("%5i. Move disc from  %6s  tower to  %6s  tower\n", 
         count, tower_out(a), tower_out(b));
}

char *tower_out(tower t){
  static char *result;
  switch (t){
    case left: result = "LEFT"; break;
    case middle: result = "MIDDLE"; break;
    case right: result = "RIGHT"; break;
  }
  return result;
}

int main(void) {
  int number_of_discs;

  printf("How many discs: ");
  scanf("%d", &number_of_discs);

  hanoi(number_of_discs, left, right, middle);
  
  return 0;
}