modules/up/src/gnug++/gcd.cc
/* [<][>][^][v][top][bottom][index][help] */
FUNCTIONS
This source file includes following functions.
- gcd
1 /*
2 Copyright (C) 1990 Free Software Foundation
3 written by Doug Lea (dl@rocky.oswego.edu)
4
5 This file is part of the GNU C++ Library. This library is free
6 software; you can redistribute it and/or modify it under the terms of
7 the GNU Library General Public License as published by the Free
8 Software Foundation; either version 2 of the License, or (at your
9 option) any later version. This library is distributed in the hope
10 that it will be useful, but WITHOUT ANY WARRANTY; without even the
11 implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
12 PURPOSE. See the GNU Library General Public License for more details.
13 You should have received a copy of the GNU Library General Public
14 License along with this library; if not, write to the Free Software
15 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
16 */
17
18 #ifdef __GNUG__
19 #pragma implementation
20 #endif
21 #include <builtin.h>
22
23
24 /*
25 common functions on built-in types
26 */
27
28 long gcd(long x, long y) // euclid's algorithm
/* [<][>][^][v][top][bottom][index][help] */
29 {
30 long a = abs(x);
31 long b = abs(y);
32
33 long tmp;
34
35 if (b > a)
36 {
37 tmp = a; a = b; b = tmp;
38 }
39 for(;;)
40 {
41 if (b == 0)
42 return a;
43 else if (b == 1)
44 return b;
45 else
46 {
47 tmp = b;
48 b = a % b;
49 a = tmp;
50 }
51 }
52 }