michael@0: /*
michael@0:  *  lap.c
michael@0:  *
michael@0:  *  Find least annihilating power of a mod m
michael@0:  *
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include <signal.h>
michael@0: 
michael@0: #include "mpi.h"
michael@0: 
michael@0: void sig_catch(int ign);
michael@0: 
michael@0: int g_quit = 0;
michael@0: 
michael@0: int main(int argc, char *argv[])
michael@0: {
michael@0:   mp_int   a, m, p, k;
michael@0: 
michael@0:   if(argc < 3) {
michael@0:     fprintf(stderr, "Usage: %s <a> <m>\n", argv[0]);
michael@0:     return 1;
michael@0:   }
michael@0: 
michael@0:   mp_init(&a);
michael@0:   mp_init(&m);
michael@0:   mp_init(&p);
michael@0:   mp_add_d(&p, 1, &p);
michael@0: 
michael@0:   mp_read_radix(&a, argv[1], 10);
michael@0:   mp_read_radix(&m, argv[2], 10);
michael@0: 
michael@0:   mp_init_copy(&k, &a);
michael@0: 
michael@0:   signal(SIGINT, sig_catch);
michael@0: #ifndef __OS2__
michael@0:   signal(SIGHUP, sig_catch);
michael@0: #endif
michael@0:   signal(SIGTERM, sig_catch);
michael@0: 
michael@0:   while(mp_cmp(&p, &m) < 0) {
michael@0:     if(g_quit) {
michael@0: 	int  len;
michael@0: 	char *buf;
michael@0: 
michael@0: 	len = mp_radix_size(&p, 10);
michael@0: 	buf = malloc(len);
michael@0: 	mp_toradix(&p, buf, 10);
michael@0: 	
michael@0: 	fprintf(stderr, "Terminated at: %s\n", buf);
michael@0: 	free(buf);
michael@0: 	return 1;
michael@0:     }
michael@0:     if(mp_cmp_d(&k, 1) == 0) {
michael@0:       int    len;
michael@0:       char  *buf;
michael@0: 
michael@0:       len = mp_radix_size(&p, 10);
michael@0:       buf = malloc(len);
michael@0:       mp_toradix(&p, buf, 10);
michael@0: 
michael@0:       printf("%s\n", buf);
michael@0: 
michael@0:       free(buf);
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:     mp_mulmod(&k, &a, &m, &k);
michael@0:     mp_add_d(&p, 1, &p);
michael@0:   }
michael@0: 
michael@0:   if(mp_cmp(&p, &m) >= 0) 
michael@0:     printf("No annihilating power.\n");
michael@0: 
michael@0:   mp_clear(&p);
michael@0:   mp_clear(&m);
michael@0:   mp_clear(&a);
michael@0:   return 0;
michael@0: }
michael@0: 
michael@0: void sig_catch(int ign)
michael@0: {
michael@0:   g_quit = 1;
michael@0: }