/* NM i programmering 2001
   Løsningsforslag til oppgave F
   Skrevet av Dag Langmyhr (dag@ifi.uio.no) */

#include <stdio.h>

/* find_instr: 
   A recursive function to find the instructions needed to
   produce the value x. These instructions are printed to f. */
void find_instr (FILE *f, int x)
{
  if (x < -1 || x > 1) {
    if (x%2 == 0) {
      find_instr(f, x/2);  fprintf(f, "DBL\n");  
    } else {
      find_instr(f, x-1);  fprintf(f, "INCR\n");
    }
  } else {
    fprintf(f, "%s\n", (x<0 ? "C-1" : "C+1"));
  }
}

/* main:
   The main program. It will read various numbers and use find_instr
   to print the instructions resulting in the number. */
int main (void)
{
  FILE *in_f  = fopen("yacl.in","r"), *out_f = fopen("yacl.out","w");
  int x, n_printed = 0;

  for (fscanf(in_f,"%d",&x);  x != 0;  fscanf(in_f,"%d",&x)) {
    if (n_printed++ > 0) fprintf(out_f, "\n");
    fprintf(out_f, "Constant %d\n", x);

    find_instr(out_f, x);
  }
  fclose(in_f);  fclose(out_f);  return 0;
}