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