# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1435075351 18000
# Node ID c2cbfdf528f6db84ea8e1a46476547e49f06ce0c
# Parent  ec700842d1825440aab04aee89a7f692afb35ff4
1.3.44  Ugh.  I would never use this in real life but it seems to be what they want.

diff -r ec700842d182 -r c2cbfdf528f6 algs4-c++/1.3.44
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/algs4-c++/1.3.44	Tue Jun 23 11:02:31 2015 -0500
@@ -0,0 +1,1 @@
+src/Buffer.hpp
\ No newline at end of file
diff -r ec700842d182 -r c2cbfdf528f6 algs4-c++/src/Buffer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/algs4-c++/src/Buffer.cpp	Tue Jun 23 11:02:31 2015 -0500
@@ -0,0 +1,84 @@
+// Sedgewick and Wayne, Algorithms, 4th ed. problem 1.3.44
+
+// I would never use this in real life.  It's far too inefficient.
+
+#include "Buffer.hpp"
+
+Buffer::Buffer( void ) :
+    cursor (0),
+    use_s1 (true)
+    {
+    }
+
+void Buffer::insert( char c ) {
+    if ( use_s1 ) {
+        size_t i = 0;
+        size_t max = s1.size();
+        while ( i != cursor )
+            s2.push( s1.pop() );
+        s2.push( c );
+        while ( i < max )
+            s2.push( s1.pop() );
+        }
+    else {
+        size_t i = 0;
+        size_t max = s2.size();
+        while ( i != cursor )
+            s1.push( s2.pop() );
+        s1.push( c );
+        while ( i < max )
+            s1.push( s2.pop() );
+        }
+    }
+
+char Buffer::get( void ) {
+    if ( use_s1 )
+        return s1.find( cursor );       // Need to add overloaded T find( size_t k) to Stack
+    else
+        return s2.find( cursor );
+    }
+
+char Buffer::delete( void ) {
+    if ( use_s1 ) {
+        size_t i = 0;
+        size_t max = s1.size();
+        while ( i != cursor )
+            s2.push( s1.pop() );
+        ++i;
+        while ( i < max )
+            s2.push( s1.pop() );
+        }
+    else {
+        size_t i = 0;
+        size_t max = s2.size();
+        while ( i != cursor )
+            s1.push( s2.pop() );
+        ++i;
+        while ( i < max )
+            s1.push( s2.pop() );
+        }
+
+    if ( cursor > size() )
+        cursor = size();
+    }
+
+void Buffer::left( size_t k ) {
+    if ( cursor < k )
+        cursor = 0;
+    else
+        cursor -= k;
+    }
+
+void Buffer::right( size_t k ) {
+    if ( size() - cursor < k )
+        cursor = size();
+    else
+        cursor += k;
+    }
+
+size_t Buffer::size( void ) {
+    if ( use_s1 )
+        return s1.size();
+    else
+        return s2.size();
+    }
diff -r ec700842d182 -r c2cbfdf528f6 algs4-c++/src/Buffer.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/algs4-c++/src/Buffer.hpp	Tue Jun 23 11:02:31 2015 -0500
@@ -0,0 +1,34 @@
+// Sedgewick and Wayne, Algorithms, 4th ed. problem 1.3.44
+
+// Two stack implementation.  I don't know why anyone would actually want to use
+// an implmentation like this, but it's what they suggested in the problem.  I
+// guess it's just an "exercise" after all.
+
+
+#ifndef BUFFER_HPP
+#define BUFFER_HPP
+
+#include <cstddef>
+
+#include "Stack.hpp"
+
+class Buffer {
+public:
+    Buffer( void );
+
+    void insert( char c );
+    char get( void );
+    char delete( void );
+    void left( size_t k );
+    void right( size_t k );
+    size_t size( void );
+
+private:
+    size_t cursor;
+
+    bool use_s1;
+    Stack<char> s1;
+    Stack<char> s2;
+    };
+
+#endif