DGtal  0.9.3
convergents-biginteger.cpp
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1 
40 #include <iostream>
43 #include "DGtal/arithmetic/LighterSternBrocot.h"
45 
47 
48 using namespace DGtal;
49 
51 
52 void usage( int, char** argv )
53 {
54  std::cerr << "Usage: " << argv[ 0 ] << " <p> <q>" << std::endl;
55  std::cerr << "\t - computes the successive convergent of the fraction p / q." << std::endl;
56 }
57 
61 int main( int argc, char** argv )
62 {
63  if ( argc < 3 )
64  {
65  usage( argc, argv );
66  return 1;
67  }
68  std::string inputP = argv[ 1 ];
69  std::string inputQ = argv[ 2 ];
70 
72  typedef BigInteger Integer;
73  typedef DGtal::int64_t Quotient;
74  typedef LighterSternBrocot<Integer, Quotient, StdMapRebinder> SB; // the type of the Stern-Brocot tree
75  typedef SB::Fraction Fraction; // the type for fractions
76  typedef Fraction::ConstIterator ConstIterator; // the iterator type for visiting quotients
77  typedef Fraction::Value Value; // the value of the iterator, a pair (quotient,depth).
79 
81  Integer p( inputP );
82  Integer q( inputQ );
83  Fraction f( p, q ); // fraction p/q
85 
87  // Visit quotients u_k as pair (u_k,k)
88  std::cout << "z = ";
89  ConstIterator itbegin = f.begin(), itend = f.end();
90  for ( ConstIterator it = itbegin; it != itend; ++it )
91  {
92  Value u = *it;
93  std::cout << ( ( it == itbegin ) ? "[" : "," )
94  << u.first;
95  }
96  std::cout << "]" << std::endl;
98 
100  Fraction g; // fraction null, 0/0, invalid
101  for ( ConstIterator it = itbegin; it != itend; ++it )
102  {
103  Value u = *it;
104  std::cout << "z_" << u.second << " = ";
105  g.push_back( u ); // add (u_i,i) to existing fractions
106  std::cout << g.p() << " / " << g.q() << std::endl;
107  }
109  return 0;
110 }
111 
MyDigitalSurface::ConstIterator ConstIterator
mpz_class BigInteger
Multi-precision integer with GMP implementation.
Definition: BasicTypes.h:79
int main(int argc, char **argv)
void usage(int, char **argv)
DGtal is the top-level namespace which contains all DGtal functions and types.
Aim: The Stern-Brocot tree is the tree of irreducible fractions. This class allows to construct it pr...
boost::int64_t int64_t
signed 94-bit integer.
Definition: BasicTypes.h:74