runner% cat hanoi.c
/* Towers of Hanoi program */
/* Written by N.R. Wagner, 28 Jan 1998 */
#include <stdio.h>

void move(int start, int temp, int end, int n);

void main()
{
   int n;
   scanf("%i", &n);
   move(1, 2, 3, n);
}

void move(int start, int temp, int end, int n)
{
   static int step = 0;
   if (n > 0){
      move(start, end, temp, n-1);
      printf("Step %2i:"
        " Move disk %i from %i to %i.\n",
         ++step, n, start, end);
      move(temp, start, end, n-1);
   }
}

runner% lint -m -u hanoi.c

function returns value which is always ignored
    printf              scanf           
runner% cc -o hanoi hanoi.c
runner% hanoi
1
Step  1: Move disk 1 from 1 to 3.
runner% hanoi
2
Step  1: Move disk 1 from 1 to 2.
Step  2: Move disk 2 from 1 to 3.
Step  3: Move disk 1 from 2 to 3.
runner% hanoi
3
Step  1: Move disk 1 from 1 to 3.
Step  2: Move disk 2 from 1 to 2.
Step  3: Move disk 1 from 3 to 2.
Step  4: Move disk 3 from 1 to 3.
Step  5: Move disk 1 from 2 to 1.
Step  6: Move disk 2 from 2 to 3.
Step  7: Move disk 1 from 1 to 3.





runner% hanoi
4
Step  1:  Move disk 1 from 1 to 2.
Step  2:  Move disk 2 from 1 to 3.
Step  3:  Move disk 1 from 2 to 3.
Step  4:  Move disk 3 from 1 to 2.
Step  5:  Move disk 1 from 3 to 1.
Step  6:  Move disk 2 from 3 to 2.
Step  7:  Move disk 1 from 1 to 2.
Step  8:  Move disk 4 from 1 to 3.
Step  9:  Move disk 1 from 2 to 3.
Step 10: Move disk 2 from 2 to 1.
Step 11: Move disk 1 from 3 to 1.
Step 12: Move disk 3 from 2 to 3.
Step 13: Move disk 1 from 1 to 2.
Step 14: Move disk 2 from 1 to 3.
Step 15: Move disk 1 from 2 to 3.
runner% hanoi
5
Step  1:  Move disk 1 from 1 to 3.
Step  2:  Move disk 2 from 1 to 2.
Step  3:  Move disk 1 from 3 to 2.
Step  4:  Move disk 3 from 1 to 3.
Step  5:  Move disk 1 from 2 to 1.
Step  6:  Move disk 2 from 2 to 3.
Step  7:  Move disk 1 from 1 to 3.
Step  8:  Move disk 4 from 1 to 2.
Step  9:  Move disk 1 from 3 to 2.
Step 10: Move disk 2 from 3 to 1.
Step 11: Move disk 1 from 2 to 1.
Step 12: Move disk 3 from 3 to 2.
Step 13: Move disk 1 from 1 to 3.
Step 14: Move disk 2 from 1 to 2.
Step 15: Move disk 1 from 3 to 2.
Step 16: Move disk 5 from 1 to 3.
Step 17: Move disk 1 from 2 to 1.
Step 18: Move disk 2 from 2 to 3.
Step 19: Move disk 1 from 1 to 3.
Step 20: Move disk 3 from 2 to 1.
Step 21: Move disk 1 from 3 to 2.
Step 22: Move disk 2 from 3 to 1.
Step 23: Move disk 1 from 2 to 1.
Step 24: Move disk 4 from 2 to 3.
Step 25: Move disk 1 from 1 to 3.
Step 26: Move disk 2 from 1 to 2.
Step 27: Move disk 1 from 3 to 2.
Step 28: Move disk 3 from 1 to 3.
Step 29: Move disk 1 from 2 to 1.
Step 30: Move disk 2 from 2 to 3.
Step 31: Move disk 1 from 1 to 3.
runner%