From: Sam Moore <matches@ucc.asn.au>
Date: Sat, 5 Jul 2014 09:33:39 +0000 (+0800)
Subject: Division less buggy, still slow
X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fcode.git;a=commitdiff_plain;h=a7da45c62d5a0604785479f5dfeb1c2a65d0f9de

Division less buggy, still slow

Ok I need to put more thought into this. Or just look it up.
---

diff --git a/src/arbint.cpp b/src/arbint.cpp
index d61dabc..748330f 100644
--- a/src/arbint.cpp
+++ b/src/arbint.cpp
@@ -108,16 +108,32 @@ Arbint & Arbint::operator*=(const Arbint & mul)
 
 void Arbint::Division(const Arbint & div, Arbint & result, Arbint & remainder) const
 {
-	//TODO: Optimise?
+	if (div == Arbint(1L))
+	{
+		result = *this;
+		remainder = 0L;
+		return;
+	}
+	if (div == *this)
+	{
+		result = 1L;
+		remainder = 0L;
+		return;
+	}
+
+
+	result = 0L;	
 	remainder = *this;
-	result = 0L;
-	while ((remainder -= div) > Arbint(0L))
+	Arbint next_rem(remainder);
+	while ((next_rem -= div) >= Arbint(0L))
 	{
-		//Debug("Remainder %c%s", remainder.SignChar(), remainder.DigitStr().c_str());
-		//Debug("Result %c%s + 1", result.SignChar(), result.DigitStr().c_str());
-		result += 1;
+		//Debug("%li - %li = %li", digit_t(remainder), digit_t(div), digit_t(next_rem));
+		//Debug("Sign is %d", next_rem.m_sign);
+		remainder = next_rem;
+		result += 1L;
 	}
-	remainder += div;
+	
+	
 }
 
 Arbint & Arbint::operator+=(const Arbint & add)
@@ -217,7 +233,8 @@ bool Arbint::IsZero() const
 
 bool Arbint::operator==(const Arbint & equ) const
 {
-	if (m_sign != equ.m_sign) return false;
+	if (m_sign != equ.m_sign) 
+		return false;
 	unsigned min_size = m_digits.size();
 	const Arbint * larger = &equ;
 	if (m_digits.size() > equ.m_digits.size())
diff --git a/src/arbint.h b/src/arbint.h
index 12f8302..4b819b9 100644
--- a/src/arbint.h
+++ b/src/arbint.h
@@ -101,7 +101,7 @@ namespace IPDF
 			
 			inline bool operator>=(const Arbint & leq) const 
 			{
-				return (this->operator==(leq) || this->operator<(leq));
+				return (this->operator==(leq) || this->operator>(leq));
 			}
 			inline bool operator>(const Arbint & grea) const
 			{
diff --git a/src/rational.h b/src/rational.h
index ce1a767..6269ef1 100644
--- a/src/rational.h
+++ b/src/rational.h
@@ -16,9 +16,15 @@ namespace IPDF
 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);
@@ -29,6 +35,8 @@ T gcd(const T & a, const T & b)
 template <class T>
 T gcd(const T & p, const T & q)
 {
+
+
 	T g(1);
 	T big(p);
 	T small(q);
@@ -41,11 +49,14 @@ T gcd(const T & p, const T & q)
 		return g;
 	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
@@ -80,6 +91,7 @@ struct Rational
 			return;
 		}
 		T g = gcd(T(llabs(P)),T(llabs(Q)));
+		Debug("Got gcd!");
 		P /= g;
 		Q /= g;
 	}
diff --git a/src/tests/arb.cpp b/src/tests/arb.cpp
index b6e58cb..00bfefb 100644
--- a/src/tests/arb.cpp
+++ b/src/tests/arb.cpp
@@ -49,6 +49,7 @@ int main(int argc, char ** argv)
 		assert((arb_a/arb_b).AsDigit() == a / b);
 		assert((arb_a%arb_b).AsDigit() == a % b);
 	}
-	printf("All tests successful!\n");
+	printf("All single digit tests successful!\n");
+	
 	return 0;
 }
diff --git a/src/tests/arbrationals.cpp b/src/tests/arbrationals.cpp
new file mode 100644
index 0000000..3af559f
--- /dev/null
+++ b/src/tests/arbrationals.cpp
@@ -0,0 +1,32 @@
+/**
+ * @file arbrationals.cpp
+ * @brief Tests Rational<Arbint>
+ */
+ 
+#include "rational.h"
+#include "arbint.h"
+
+#define TEST_CASES 100
+
+using namespace std;
+using namespace IPDF;
+
+int main(int argc, char ** argv)
+{
+	for (unsigned i = 0; i < TEST_CASES; ++i)
+	{
+		Debug("Cycle %u",i);
+		Arbint p1 = 1L;//rand();
+		Arbint q1 = 2L;//rand();
+		Arbint p2 = rand();
+		Arbint q2 = rand();
+		Debug("Construct rationals");
+		Rational<Arbint> a(p1, q1);
+		Debug("Constructed a %u\n",i);
+		Rational<Arbint> b(p2, q2);
+		Debug("Constructed b %u\n",i);
+		
+		
+	}
+	printf("Tests done");
+}