#include "common.h"
#include <cmath>
#include <cassert>
+#include "arbint.h"
namespace IPDF
{
+
+template <class T> T Tabs(const T & a)
+{
+ return abs(a);
+}
+template <> Arbint Tabs(const Arbint & a);
-/** Greatest Common Divisor - Euclid's algorithm **/
+/* Recursive version of GCD
template <class T>
T gcd(const T & a, const T & b)
{
- if (a == 1 || a == 0) return 1;
- if (b == 0) return a;
- if (b == a) return a;
+ Debug("Called on %li/%li", int64_t(a), int64_t(b));
+ if (a == T(1) || a == T(0)) return T(1);
+ if (b == T(0)) return a;
+ if (b == a)
+ {
+ Debug("Equal!");
+ return a;
+ }
+ Debug("Not equal!");
if (a > b) return gcd(a-b,b);
return gcd(a, b-a);
}
+*/
-/*
+/** Greatest Common Divisor of p and q **/
template <class T>
T gcd(const T & p, const T & q)
{
- Debug("p/q = %
+
+
T g(1);
T big(p);
T small(q);
big = q;
small = p;
}
- if (small == 0)
+ if (small == T(0))
return g;
- while ((g = big % small) > 0)
+ while ((g = big % small) > T(0))
{
+ //Debug("big = %li, small = %li", int64_t(big), int64_t(small));
big = small;
small = g;
+ //Debug("Loop %u", ++count);
}
return small;
-}
-*/
+}
+
+
template <class T = int64_t>
struct Rational
{
/** Construct from a double.**/
- Rational(double d = 0) : P(d*1e3), Q(1e3) // Possibly the worst thing ever...
+ Rational(double d=0) : P(d*1e6), Q(1e6) // Possibly the worst thing ever...
{
Simplify();
- //CheckAccuracy(d, "Construct from double");
}
Rational(const T & _P, const T & _Q) : P(_P), Q(_Q)
void Simplify()
{
- if (Q < 0)
+ if (Q < T(0))
{
- P = (P < 0) ? -P : P;
+ P = -P;
Q = -Q;
}
-
- T g = gcd(llabs(P),llabs(Q));
+ if (P == T(0))
+ {
+ Q = T(1);
+ return;
+ }
+ if (P == Q)
+ {
+ P = Q = T(1);
+ return;
+ }
+ T g = gcd(Tabs(P), Tabs(Q));
+ //Debug("Got gcd!");
P /= g;
Q /= g;
}
bool operator>=(const Rational & r) const {return *this == r || *this > r;}
bool operator!=(const Rational & r) const {return !(*this == r);}
-
-
- /*
Rational operator+(const Rational & r) const
{
- Rational result = (r.P == 0) ? Rational(P,Q) : Rational(P*r.Q + r.P*Q, Q*r.Q);
- result.CheckAccuracy(ToDouble() + r.ToDouble(),"+");
+ Rational result = (r.P == T(0)) ? Rational(P,Q) : Rational(P*r.Q + r.P*Q, Q*r.Q);
+ //if (!result.CheckAccuracy(ToDouble() * r.ToDouble(),"+"))
+ //{
+ // Debug("This is %s (%f) and r is %s (%f)", Str().c_str(), ToDouble(), r.Str().c_str(), r.ToDouble());
+ //}
return result;
}
Rational operator-(const Rational & r) const
{
- Rational result = (r.P == 0) ? Rational(P,Q) : Rational(P*r.Q - r.P*Q, Q*r.Q);
- result.CheckAccuracy(ToDouble() - r.ToDouble(),"-");
+ Rational result = (r.P == T(0)) ? Rational(P,Q) : Rational(P*r.Q - r.P*Q, Q*r.Q);
+ //result.CheckAccuracy(ToDouble() - r.ToDouble(),"-");
return result;
}
- */
Rational operator*(const Rational & r) const
{
Rational result(P * r.P, Q * r.Q);
- if (!result.CheckAccuracy(ToDouble() * r.ToDouble(),"*"))
- {
- Debug("This is %s (%f) and r is %s (%f)", Str().c_str(), ToDouble(), r.Str().c_str(), r.ToDouble());
- }
+ //if (!result.CheckAccuracy(ToDouble() * r.ToDouble(),"*"))
+ //{
+ // Debug("This is %s (%f) and r is %s (%f)", Str().c_str(), ToDouble(), r.Str().c_str(), r.ToDouble());
+ //}
return result;
}
Rational operator/(const Rational & r) const
{
- Rational result = (r.P == 0) ? Rational(P,Q) : Rational(P*r.Q + r.P*Q, Q*r.Q);
- if (!result.CheckAccuracy(ToDouble() / r.ToDouble(),"*"))
- {
- Debug("This is %s (%f) and r is %s (%f)", Str().c_str(), ToDouble(), r.Str().c_str(), r.ToDouble());
- }
+ Rational result(P * r.Q, Q*r.P);
+ //if (!result.CheckAccuracy(ToDouble() / r.ToDouble(),"/"))
+ //{
+ // Debug("This is %s (%f) and r is %s (%f)", Str().c_str(), ToDouble(), r.Str().c_str(), r.ToDouble());
+ //}
return result;
}
- Rational operator+(const Rational & r) const {return Rational(ToDouble()+r.ToDouble());}
- Rational operator-(const Rational & r) const {return Rational(ToDouble()-r.ToDouble());}
+ /** To cheat, use these **/
+ //Rational operator+(const Rational & r) const {return Rational(ToDouble()+r.ToDouble());}
+ //Rational operator-(const Rational & r) const {return Rational(ToDouble()-r.ToDouble());}
//Rational operator*(const Rational & r) const {return Rational(ToDouble()*r.ToDouble());}
//Rational operator/(const Rational & r) const {return Rational(ToDouble()/r.ToDouble());}
- Rational & operator=(const Rational & r) {P = r.P; Q = r.Q; return *this;}
+ Rational operator-() const {Rational r(*this); r.P = -r.P;}
+ Rational & operator=(const Rational & r) {P = r.P; Q = r.Q; Simplify(); return *this;}
Rational & operator+=(const Rational & r) {this->operator=(*this+r); return *this;}
Rational & operator-=(const Rational & r) {this->operator=(*this-r); return *this;}
Rational & operator*=(const Rational & r) {this->operator=(*this*r); return *this;}
Rational & operator/=(const Rational & r) {this->operator=(*this/r); return *this;}
- double ToDouble() const {return (double)(P) / (double)(Q);}
- bool CheckAccuracy(double d, const char * msg, double threshold = 1e-6) const
+ double ToDouble() const
+ {
+ return (double)P/(double)Q;
+ }
+ bool CheckAccuracy(double d, const char * msg, double threshold = 1e-3) const
{
- double result = fabs(ToDouble() - d) / d;
+ double result = fabs(ToDouble() - d);
+ if (d != 0e0) result /= d;
if (result > threshold)
{
Warn("(%s) : Rational %s (%f) is not close enough at representing %f (%f vs %f)", msg, Str().c_str(), ToDouble(), d, result, threshold);
+ Backtrace();
return false;
}
return true;
std::string Str() const
{
std::stringstream s;
- s << (int64_t)P << "/" << (int64_t)Q;
+ s << int64_t(P) << "/" << int64_t(Q);
return s.str();
}
}
+
+
}
#endif //_RATIONAL_H