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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: mprand.h,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
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4 | * |
5 | * Generate a random multiprecision integer |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb 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 Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
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30 | #ifndef CATACOMB_MPRAND_H |
31 | #define CATACOMB_MPRAND_H |
32 | |
33 | #ifdef __cplusplus |
34 | extern "C" { |
35 | #endif |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | #ifndef CATACOMB_GRAND_H |
40 | # include "grand.h" |
41 | #endif |
42 | |
43 | #ifndef CATACOMB_MP_H |
44 | # include "mp.h" |
45 | #endif |
46 | |
47 | /*----- Functions provided ------------------------------------------------*/ |
48 | |
49 | /* --- @mprand@ --- * |
50 | * |
51 | * Arguments: @mp *d@ = destination integer |
52 | * @unsigned b@ = number of bits |
53 | * @grand *r@ = pointer to random number source |
54 | * @mpw or@ = mask to OR with low-order bits |
55 | * |
56 | * Returns: A random integer with the requested number of bits |
57 | * |
58 | * Use: Constructs an arbitrarily large pseudorandom integer. |
59 | * Assuming that the generator @r@ is good, the result is |
60 | * uniformly distributed in the interval %$[2^{b - 1}, 2^b)$%. |
61 | * The result is then ORred with the given @or@ value. This |
62 | * will often be 1, to make the result odd. |
63 | */ |
64 | |
65 | extern mp *mprand(mp */*d*/, unsigned /*b*/, grand */*r*/, mpw /*or*/); |
66 | |
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67 | /* --- @mprand_range@ --- * |
68 | * |
69 | * Arguments: @mp *d@ = destination integer |
70 | * @mp *l@ = limit for random number |
71 | * @grand *r@ = random number source |
72 | * @mpw or@ = mask for low-order bits |
73 | * |
74 | * Returns: A pseudorandom integer, unformly distributed over the |
75 | * interval %$[0, l)$%. |
76 | * |
77 | * Use: Generates a uniformly-distributed pseudorandom number in the |
78 | * appropriate range. |
79 | */ |
80 | |
81 | extern mp *mprand_range(mp */*d*/, mp */*l*/, grand */*r*/, mpw /*or*/); |
82 | |
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83 | /*----- That's all, folks -------------------------------------------------*/ |
84 | |
85 | #ifdef __cplusplus |
86 | } |
87 | #endif |
88 | |
89 | #endif |