| fe9969ff |
1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: mono.c,v 1.1 2003/09/15 02:48:54 mdw Exp $ |
| 4 | * |
| 5 | * Monoalphabetic matcher |
| 6 | * |
| 7 | * (c) 2003 Mark Wooding |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Anag: a simple wordgame helper. |
| 13 | * |
| 14 | * Anag is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * Anag is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with Anag; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: mono.c,v $ |
| 32 | * Revision 1.1 2003/09/15 02:48:54 mdw |
| 33 | * Monoalphabetic match filter. |
| 34 | * |
| 35 | */ |
| 36 | |
| 37 | /*----- Header files ------------------------------------------------------*/ |
| 38 | |
| 39 | #include "anag.h" |
| 40 | |
| 41 | /*----- Data structures ---------------------------------------------------*/ |
| 42 | |
| 43 | typedef struct node_mono { |
| 44 | node n; |
| 45 | unsigned len; |
| 46 | unsigned char *p; |
| 47 | } node_mono; |
| 48 | |
| 49 | /*----- Main code ---------------------------------------------------------*/ |
| 50 | |
| 51 | /* --- Matching --- */ |
| 52 | |
| 53 | static int n_mono(node *nn, const char *p, size_t sz) |
| 54 | { |
| 55 | node_mono *n = (node_mono *)nn; |
| 56 | unsigned map[UCHAR_MAX], imap[UCHAR_MAX]; |
| 57 | const unsigned char *q = n->p; |
| 58 | int ch, i; |
| 59 | |
| 60 | if (sz != n->len) |
| 61 | return (0); |
| 62 | memset(map, 0, sizeof(map)); |
| 63 | memset(imap, 0, sizeof(imap)); |
| 64 | while (*p) { |
| 65 | ch = *p++; |
| 66 | i = *q++; |
| 67 | if (!map[i]) { |
| 68 | if (imap[ch]) |
| 69 | return (0); |
| 70 | map[i] = ch; |
| 71 | imap[ch] = 1; |
| 72 | } else if (map[i] != ch) |
| 73 | return (0); |
| 74 | } |
| 75 | return (1); |
| 76 | } |
| 77 | |
| 78 | /* --- Node creation --- */ |
| 79 | |
| 80 | node *mono(const char *const *av) |
| 81 | { |
| 82 | unsigned char map[UCHAR_MAX]; |
| 83 | unsigned max; |
| 84 | int ch; |
| 85 | const char *p; |
| 86 | unsigned char *q; |
| 87 | |
| 88 | node_mono *n = xmalloc(sizeof(*n)); |
| 89 | n->n.func = n_mono; |
| 90 | memset(map, UCHAR_MAX, sizeof(map)); |
| 91 | max = 0; |
| 92 | p = av[0]; |
| 93 | n->len = strlen(p); |
| 94 | q = xmalloc(n->len); |
| 95 | n->p = q; |
| 96 | while (*p) { |
| 97 | ch = *p++; |
| 98 | if (map[ch] >= max) |
| 99 | map[ch] = max++; |
| 100 | *q++ = map[ch]; |
| 101 | } |
| 102 | return (&n->n); |
| 103 | } |
| 104 | |
| 105 | /*----- That's all, folks -------------------------------------------------*/ |
~mdw / anag / blame