From 7bb55b03c393b5d00914d328a16d238d17f6aa0f Mon Sep 17 00:00:00 2001
From: Mike Buland <mike@xagasoft.com>
Date: Tue, 16 Apr 2013 13:57:57 -0600
Subject: Added /, %, and = operators.

Division now works just fine, but by long division.  There are
apparently much faster ways of doing division, but as long as it works I
feel like that's a great start :)
---
 src/number.cpp | 107 ++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 91 insertions(+), 16 deletions(-)

(limited to 'src/number.cpp')

diff --git a/src/number.cpp b/src/number.cpp
index 9b6ec55..b3a33dc 100644
--- a/src/number.cpp
+++ b/src/number.cpp
@@ -29,7 +29,11 @@ Number &Number::operator=( const Bu::String &sNum )
     return *this;
 }
 
-template<typename t> t tabs( t x ) { return (x<(t)0)?(-x):x; }
+Number &Number::operator=( const Number &rhs )
+{
+    set( rhs );
+    return *this;
+}
 
 Number Number::operator+( const Number &rhs ) const
 {
@@ -87,24 +91,18 @@ Number Number::operator*( const Number &rhs ) const
 
 Number Number::operator/( const Number &rhs ) const
 {
-    if( rhs.aInt.getSize() > aInt.getSize() )
-        return Number( iOrd );
-
-    Number q( iOrd );
-
-    int iMinWidth = rhs.aInt.getSize();
-
-    Bu::println("%1\n-----").arg( aInt.toString() );
-    for( int j = aInt.getSize(); j > iMinWidth; j-- )
-    {
-        Number sub( iOrd );
-        sub.aInt.set( aInt, j-iMinWidth, iMinWidth );
-        Bu::println("%1\n%2\n----").arg( sub.toString() ).arg( rhs.toString() );
-    }
-
+    Number q( iOrd ), r( iOrd );
+    divide( rhs, q, r );
     return q;
 }
 
+Number Number::operator%( const Number &rhs ) const
+{
+    Number q( iOrd ), r( iOrd );
+    divide( rhs, q, r );
+    return r;
+}
+
 Number Number::operator-() const
 {
     Number neg( *this );
@@ -250,6 +248,13 @@ void Number::set( const Bu::String &sNum )
     }
 }
 
+void Number::set( const Number &sNum )
+{
+    aInt.set( sNum.aInt );
+    bPositive = sNum.bPositive;
+    iOrd = sNum.iOrd;
+}
+
 Bu::String Number::toString() const
 {
     if( aInt.getSize() == 0 )
@@ -272,6 +277,7 @@ Number Number::add( const Number &rhs, bool bSub ) const
 
     int iZeros = 0;
     int iCarry = 0;
+//    Bu::println("::: %1 + %2:").arg( toString() ).arg( rhs.toString() );
 
     if( bPositive == (bSub?!rhs.bPositive:rhs.bPositive))
     {
@@ -332,8 +338,77 @@ Number Number::add( const Number &rhs, bool bSub ) const
                 ret.aInt.set( j, 9-ret.aInt.get( j ));
             }
         }
+        else
+        {
+            ret.aInt.trim();
+        }
     }
 
     return ret;
 }
 
+void Number::divide( const Number &rhs, Number &q, Number &r ) const
+{
+    q.aInt.clear();
+    r = *this;
+    
+    if( rhs.aInt.getSize() > aInt.getSize() )
+        return;
+
+    if( bPositive == rhs.bPositive )
+        q.bPositive = true;
+    else
+        q.bPositive = false;
+
+    int iMinWidth = rhs.aInt.getSize();
+
+    int iAnchor = r.aInt.getSize()-iMinWidth;
+    int iSample = iMinWidth;
+    do
+    {
+//        Bu::println("%1\n-----").arg( r.aInt.toString() );
+        Number sub( iOrd );
+        for(;;)
+        {
+//            Bu::println("  -> Anchor: %1, Sample: %2").arg( iAnchor ).arg( iSample );
+            sub.aInt.set( r.aInt, iAnchor, iSample );
+//            Bu::println("%1\n%2\n----").arg( sub.toString() ).arg( rhs.toString() );
+            if( sub < rhs )
+            {
+                iSample++;
+                iAnchor--;
+                if( iAnchor < 0 )
+                {
+//                    Bu::println("[Inner exit] Complete: q = %1, r = %2").arg( q.toString() ).arg( r.toString() );
+                    return;
+                }
+            }
+            else
+                break;
+        }
+
+        Number x( iOrd );
+        int iRes = 0;
+        for( ; x <= sub; iRes++, x = x + rhs ) { }
+        x = sub - (x - rhs);
+        for( int j = 0; iAnchor+j >= 0 && j < x.aInt.getSize(); j++ )
+            r.aInt.set( iAnchor+j, x.aInt.get( j ) );
+        while( r.aInt.getSize() > iAnchor+x.aInt.getSize() )
+            r.aInt.remove();
+//        Bu::println(" -> Post remainder patch: %1 -> %2").
+//            arg( x.toString() ).arg( r.toString() );
+
+//        Bu::println("%1 (%2)").arg( iRes-1 ).arg( x.toString() );
+        while( q.aInt.getSize() <= iAnchor )
+            q.aInt.append(0);
+        q.aInt.set( iAnchor, iRes-1 );
+
+        iSample = iMinWidth;
+        iAnchor = r.aInt.getSize()-iMinWidth;
+//        Bu::println("  -> new Anchor: %1, Sample: %2").arg( iAnchor ).
+//            arg( iSample );
+    } while( iAnchor >= 0 );
+
+//    Bu::println("Complete: q = %1, r = %2").arg( q.toString() ).arg( r.toString() );
+}
+
-- 
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