git.distorted.org.uk Git - u/mdw/catacomb/blob - utils/naf.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "mp.h"
   5 #include "mptext.h"
   6
   7
   8 int main(int argc, char *argv[])
   9 {
  10   mp *x;
  11   mpscan sc;
  12   unsigned long d, i;
  13   enum { Z = 0, Z1 = 2, X = 4, X0 = 6 };
  14   unsigned st = Z;
  15
  16   x = mp_readstring(MP_NEW, argv[1], 0, 0);
  17   d = mp_bits(x);
  18
  19   for (i = 0, mp_scan(&sc, x); mp_step(&sc); i++) {
  20     switch (st | mp_bit(&sc)) {
  21       case  Z | 1: st = Z1; printf("\t-> Z1\n"); break;
  22       case Z1 | 0: st =  Z; printf("+ %lu\t-> Z\n", i - 1); break;
  23       case Z1 | 1: st =  X; printf("- %lu\t-> X\n", i - 1); break;
  24       case  X | 0: st = X0; printf("\t-> X0\n"); break;
  25       case X0 | 1: st =  X; printf("- %lu\t-> X\n", i - 1); break;
  26       case X0 | 0: st =  Z; printf("+ %lu\t-> Z\n", i - 1); break;
  27     }
  28   }
  29   switch (st) {
  30     case Z1: case X0: printf("+ %lu\n", i - 1); break;
  31     case X: printf("+ %lu\n", i); break;
  32   }
  33 }