libstdc++-v3/testsuite/ext/pb_ds/example/trie_dna.cc

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 2, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  19 // MA 02111-1307, USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
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  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
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  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  32
  33 // Permission to use, copy, modify, sell, and distribute this software
  34 // is hereby granted without fee, provided that the above copyright
  35 // notice appears in all copies, and that both that copyright notice
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  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
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  40 // warranty.
  41
  42 /**
  43  * @file trie_dna_example.cpp
  44  * An example showing how to use a trie for storing DNA strings.
  45  */
  46
  47 /**
  48  * This example shows how to use a PATRICIA trie for storing
  49  DNA strings. The main point is writing element-access traits
  50  for these strings.
  51 */
  52
  53 #include <cassert>
  54 #include <iostream>
  55 #include <cstdlib>
  56 #include <ext/pb_ds/assoc_container.hpp>
  57 #include <ext/pb_ds/trie_policy.hpp>
  58
  59 using namespace std;
  60 using namespace __gnu_pbds;
  61
  62 // DNA is represented by a string.
  63 typedef string dna_t;
  64
  65 // Following is an element access traits for a DNA string.
  66 struct dna_string_e_access_traits
  67 {
  68 public:
  69   typedef size_t size_type;
  70   typedef dna_t key_type;
  71   typedef const key_type& const_key_reference;
  72   typedef char e_type;
  73   typedef string::const_iterator const_iterator;
  74
  75   enum
  76     {
  77       // Number of distinct elements. This is 4 = |{'A', 'C', 'G', 'T'}|
  78       max_size = 4
  79     };
  80
  81   // Returns a const_iterator to the firstelement of r_key.
  82   inline static const_iterator
  83   begin(const_key_reference r_key)
  84   { return r_key.begin(); }
  85
  86   // Returns a const_iterator to the after-lastelement of r_key.
  87   inline static const_iterator
  88   end(const_key_reference r_key)
  89   { return r_key.end(); }
  90
  91   // Maps an element to a position.
  92   inline static size_t
  93   e_pos(e_type e)
  94   {
  95     switch(e)
  96       {
  97       case 'A':
  98         return 0;
  99       case 'C':
 100         return 1;
 101       case 'G':
 102         return 2;
 103       case 'T':
 104         return 3;
 105       default:
 106         std::abort();
 107       };
 108   }
 109 };
 110
 111 // A PATRICIA trie with DNA string element-access traits.
 112 typedef dna_string_e_access_traits traits_type;
 113 typedef trie<dna_t, string, traits_type> trie_type;
 114
 115 int main()
 116 {
 117   trie_type t;
 118
 119   // Now map some DNAs to diseases in namespace STD.
 120   t["ACCGGTTACTGGTA"] = "gonorrhea";
 121   t["CCGTTATCGGTA"] = "syphlis";
 122
 123   // Check gonorrhea already contracted.
 124   assert(t.find("ACCGGTTACTGGTA") != t.end());
 125
 126   return 0;
 127 }
 128