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Diffstat (limited to 'OpenSim/Framework/PrimeNumberHelper.cs')
-rw-r--r-- | OpenSim/Framework/PrimeNumberHelper.cs | 114 |
1 files changed, 0 insertions, 114 deletions
diff --git a/OpenSim/Framework/PrimeNumberHelper.cs b/OpenSim/Framework/PrimeNumberHelper.cs deleted file mode 100644 index 39079de..0000000 --- a/OpenSim/Framework/PrimeNumberHelper.cs +++ /dev/null | |||
@@ -1,114 +0,0 @@ | |||
1 | /* | ||
2 | * Copyright (c) Contributors, http://opensimulator.org/ | ||
3 | * See CONTRIBUTORS.TXT for a full list of copyright holders. | ||
4 | * | ||
5 | * Redistribution and use in source and binary forms, with or without | ||
6 | * modification, are permitted provided that the following conditions are met: | ||
7 | * * Redistributions of source code must retain the above copyright | ||
8 | * notice, this list of conditions and the following disclaimer. | ||
9 | * * Redistributions in binary form must reproduce the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer in the | ||
11 | * documentation and/or other materials provided with the distribution. | ||
12 | * * Neither the name of the OpenSimulator Project nor the | ||
13 | * names of its contributors may be used to endorse or promote products | ||
14 | * derived from this software without specific prior written permission. | ||
15 | * | ||
16 | * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY | ||
17 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | ||
18 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | ||
19 | * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY | ||
20 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | ||
21 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | ||
22 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | ||
23 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||
24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
25 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
26 | */ | ||
27 | using System; | ||
28 | |||
29 | namespace OpenSim.Framework | ||
30 | { | ||
31 | /// <summary> | ||
32 | /// Utility class that is used to find small prime numbers and test is number prime number. | ||
33 | /// </summary> | ||
34 | public static class PrimeNumberHelper | ||
35 | { | ||
36 | /// <summary> | ||
37 | /// Precalculated prime numbers. | ||
38 | /// </summary> | ||
39 | private static readonly int[] Primes = new int[] | ||
40 | { | ||
41 | 3, 7, 11, 17, 23, 29, 37, 47, 59, 71, 89, 107, 131, 163, 197, 239, | ||
42 | 293, 353, 431, 521, 631, 761, 919, 1103, 1327, 1597, 1931, 2333, | ||
43 | 2801, 3371, 4049, 4861, 5839, 7013, 8419, 10103, 12143, 14591, | ||
44 | 17519, 21023, 25229, 30293, 36353, 43627, 52361, 62851, 75431, | ||
45 | 90523, 108631, 130363, 156437, 187751, 225307, 270371, 324449, | ||
46 | 389357, 467237, 560689, 672827, 807403, 968897, 1162687, 1395263, | ||
47 | 1674319, 2009191, 2411033, 2893249, 3471899, 4166287, 4999559, | ||
48 | 5999471, 7199369 | ||
49 | }; | ||
50 | |||
51 | /// <summary> | ||
52 | /// Get prime number that is equal or larger than <see cref="min"/>. | ||
53 | /// </summary> | ||
54 | /// <param name="min"> | ||
55 | /// Minimal returned prime number. | ||
56 | /// </param> | ||
57 | /// <returns> | ||
58 | /// Primer number that is equal or larger than <see cref="min"/>. If <see cref="min"/> is too large, return -1. | ||
59 | /// </returns> | ||
60 | public static int GetPrime( int min ) | ||
61 | { | ||
62 | if( min <= 2 ) | ||
63 | return 2; | ||
64 | |||
65 | if( Primes[ Primes.Length - 1 ] < min ) | ||
66 | { | ||
67 | for( var i = min | 1 ; i < 0x7FFFFFFF ; i += 2 ) | ||
68 | { | ||
69 | if( IsPrime( i ) ) | ||
70 | return i; | ||
71 | } | ||
72 | |||
73 | return -1; | ||
74 | } | ||
75 | |||
76 | for( var i = Primes.Length - 2 ; i >= 0 ; i-- ) | ||
77 | { | ||
78 | if( min == Primes[ i ] ) | ||
79 | return min; | ||
80 | |||
81 | if( min > Primes[ i ] ) | ||
82 | return Primes[ i + 1 ]; | ||
83 | } | ||
84 | |||
85 | return 2; | ||
86 | } | ||
87 | |||
88 | /// <summary> | ||
89 | /// Just basic Sieve of Eratosthenes prime number test. | ||
90 | /// </summary> | ||
91 | /// <param name="candinate"> | ||
92 | /// Number that is tested. | ||
93 | /// </param> | ||
94 | /// <returns> | ||
95 | /// true, if <see cref="candinate"/> is prime number; otherwise false. | ||
96 | /// </returns> | ||
97 | public static bool IsPrime( int candinate ) | ||
98 | { | ||
99 | if( (candinate & 1) == 0 ) | ||
100 | |||
101 | // Even number - only prime if 2 | ||
102 | return candinate == 2; | ||
103 | |||
104 | var upperBound = (int) Math.Sqrt( candinate ); | ||
105 | for( var i = 3 ; i < upperBound ; i += 2 ) | ||
106 | { | ||
107 | if( candinate % i == 0 ) | ||
108 | return false; | ||
109 | } | ||
110 | |||
111 | return true; | ||
112 | } | ||
113 | } | ||
114 | } | ||