[11] | 1 | // Simple random number generator class taken from nlojet++.
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| 2 | // Some doxygen-style comments added by Gavin Salam, August 2006.
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| 3 | // $Id: BasicRandom.hh,v 1.1 2008-11-06 14:32:09 ovyn Exp $
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| 4 | //
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| 5 | // Copyright (C) 2002 Zoltan Nagy
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| 6 | //
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| 7 | // This program is free software; you can redistribute it and/or modify
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| 8 | // it under the terms of the GNU General Public License as published by
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| 9 | // the Free Software Foundation; either version 2 of the License, or
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| 10 | // (at your option) any later version.
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| 11 | //
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| 12 | // This program is distributed in the hope that it will be useful,
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| 13 | // but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 14 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 15 | // GNU General Public License for more details.
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| 16 | //
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| 17 | // You should have received a copy of the GNU General Public License
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| 18 | // along with this program; if not, write to the Free Software
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| 19 | // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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| 20 | #ifndef __FASTJET_BASICRANDOM_HH__
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| 21 | #define __FASTJET_BASICRANDOM_HH__ 1
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| 22 |
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| 23 | // Standard includes
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| 24 | #include <iostream>
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| 25 | #include <vector>
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| 26 | #include <cassert>
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| 27 | #include "Utilities/Fastjet/include/fastjet/internal/base.hh"
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| 28 |
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| 29 | FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
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| 30 |
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| 31 | template<typename _Tp> class BasicRandom {
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| 32 | public:
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| 33 | typedef _Tp value_type;
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| 34 | typedef unsigned int size_type;
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| 35 | typedef value_type* pointer;
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| 36 |
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| 37 | // give pseudo random numbers
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| 38 | value_type operator() ();
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| 39 | void operator() (size_type, pointer);
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| 40 |
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| 41 | // (re)initialize the random number generator
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| 42 | void randomize(void *);
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| 43 |
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| 44 | // minimum and maximum values
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| 45 | static value_type min();
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| 46 | static value_type max();
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| 47 |
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| 48 | // print the informations about the generator to the stream
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| 49 | void print_info(std::ostream& __os = std::cout);
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| 50 | };
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| 51 |
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| 52 | // default random generator
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| 53 | int __default_random_generator(int *__iseed);
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| 54 |
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| 55 |
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| 56 | // specializations
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| 57 | template<>
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| 58 | class BasicRandom<int>
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| 59 | {
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| 60 | public:
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| 61 | typedef int value_type;
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| 62 | typedef unsigned int size_type;
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| 63 | typedef value_type* pointer;
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| 64 |
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| 65 | // constructors
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| 66 | explicit BasicRandom(int __s1 = 12345, int __s2 = 67890) {
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| 67 | _M_iseed[0] = __s1;
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| 68 | _M_iseed[1] = __s2;
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| 69 | }
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| 70 |
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| 71 | // give pseudo random numbers
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| 72 | value_type operator() () {
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| 73 | return __default_random_generator(_M_iseed);
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| 74 | }
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| 75 |
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| 76 | void operator() (size_type __n, pointer __res) {
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| 77 | for(size_type __i = 0; __i < __n; __i++)
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| 78 | __res[__i] = __default_random_generator(_M_iseed);
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| 79 | }
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| 80 |
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| 81 | // (re)initialize the random number generator
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| 82 | void randomize(void *__iseed) {
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| 83 | int *__new_seed = (int*) __iseed;
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| 84 | _M_iseed[0] = __new_seed[0];
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| 85 | _M_iseed[1] = __new_seed[1];
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| 86 | }
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| 87 |
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| 88 | void set_status(const std::vector<int> & __iseed) {
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| 89 | assert(__iseed.size() >= 2);
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| 90 | _M_iseed[0] = __iseed[0];
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| 91 | _M_iseed[1] = __iseed[1];
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| 92 | }
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| 93 |
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| 94 | void get_status(std::vector<int> & __iseed) {
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| 95 | __iseed.resize(2);
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| 96 | __iseed[0] = _M_iseed[0];
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| 97 | __iseed[1] = _M_iseed[1];
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| 98 | }
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| 99 |
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| 100 | // minimum and maximum values
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| 101 | inline static value_type min() { return 0;}
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| 102 | inline static value_type max() { return 2147483647;}
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| 103 |
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| 104 | // print the informations about the generator to the stream
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| 105 | void print_info(std::ostream& __os = std::cout) {
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| 106 | __os<<"BasicRandom<int> : "<<_M_iseed[0]<<", "<<_M_iseed[1]<<std::endl;
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| 107 | }
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| 108 |
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| 109 | private:
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| 110 | int _M_iseed[2];
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| 111 | };
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| 112 |
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| 113 |
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| 114 | /// template specialization (double) for the BasicRandom template class.
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| 115 | template<> class BasicRandom<double> {
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| 116 | public:
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| 117 | typedef double value_type;
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| 118 | typedef unsigned int size_type;
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| 119 | typedef value_type* pointer;
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| 120 |
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| 121 | /// constructor that takes two integers to specify the seed
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| 122 | explicit BasicRandom(int __s1 = 12345, int __s2 = 67890) {
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| 123 | _M_iseed[0] = __s1;
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| 124 | _M_iseed[1] = __s2;
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| 125 | }
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| 126 |
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| 127 | /// return a single pseudorandom double number, in the range 0.0 to 1.0
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| 128 | /// (not sure whether this range is open or closed)
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| 129 | value_type operator() () {
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| 130 | return 4.6566128752457969241e-10*__default_random_generator(_M_iseed);
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| 131 | }
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| 132 |
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| 133 | /// given a pointer __res to the beginning of an array, fill that array
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| 134 | /// with __n random numbers
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| 135 | void operator() (size_type __n, pointer __res) {
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| 136 | for(size_type __i = 0; __i < __n; __i++)
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| 137 | __res[__i] = this -> operator()();
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| 138 | }
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| 139 |
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| 140 | /// (re)initialize the random number generator from an array of seeds
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| 141 | void randomize(void *__iseed) {
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| 142 | int *__new_seed = (int*) __iseed;
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| 143 | _M_iseed[0] = __new_seed[0];
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| 144 | _M_iseed[1] = __new_seed[1];
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| 145 | }
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| 146 |
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| 147 | void set_status(const std::vector<int> & __iseed) {
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| 148 | assert(__iseed.size() >= 2);
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| 149 | _M_iseed[0] = __iseed[0];
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| 150 | _M_iseed[1] = __iseed[1];
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| 151 | }
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| 152 |
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| 153 | void get_status(std::vector<int> & __iseed) {
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| 154 | __iseed.resize(2);
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| 155 | __iseed[0] = _M_iseed[0];
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| 156 | __iseed[1] = _M_iseed[1];
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| 157 | }
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| 158 |
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| 159 | /// minimum value returned by the generator
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| 160 | inline static value_type min() { return 0.0;}
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| 161 | /// maximum value returned by the generator
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| 162 | inline static value_type max() { return 1.0;}
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| 163 |
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| 164 | /// print information about the generator to the stream
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| 165 | void print_info(std::ostream& __os = std::cout) {
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| 166 | __os<<"BasicRandom<double> : "<<_M_iseed[0]<<", "<<_M_iseed[1]<<std::endl;
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| 167 | }
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| 168 |
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| 169 | private:
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| 170 | int _M_iseed[2];
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| 171 | };
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| 172 |
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| 173 | // globally defined random number generator
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| 174 | extern BasicRandom<int> _G_random_int;
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| 175 | extern BasicRandom<double> _G_random_double;
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| 176 |
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| 177 |
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| 178 | FASTJET_END_NAMESPACE
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| 179 |
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| 180 | #endif // __FASTJET_BASICRANDOM_HH__
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| 181 |
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