# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1432875226 18000
# Node ID 310618f5e32a9bfe777ac4bd0642a2249c65d02b
# Parent  ca59e5f5b29e29a77bc0d002bc607b631856b9e3
Fleshed out ResizingArrayStack with an iterator.

diff -r ca59e5f5b29e -r 310618f5e32a algs4-c++/src/ResizingArrayStack.cpp
--- a/algs4-c++/src/ResizingArrayStack.cpp	Tue May 26 18:18:16 2015 -0500
+++ b/algs4-c++/src/ResizingArrayStack.cpp	Thu May 28 23:53:46 2015 -0500
@@ -1,5 +1,5 @@
-// g++ -std=c++0x ResizingArrayStack.cpp
-// g++ -std=c++11 ResizingArrayStack.cpp
+// g++ -D RESIZINGARRAYSTACK_MAIN -std=c++0x ResizingArrayStack.cpp
+// g++ -D RESIZINGARRAYSTACK_MAIN -std=c++11 ResizingArrayStack.cpp
 
 
 #include "ResizingArrayStack.hpp"
@@ -9,28 +9,31 @@
 
 #include <iostream>
 
-template <typename T> ResizingArrayStack<T>::ResizingArrayStack( void ) :
+template <typename T>
+ResizingArrayStack<T>::ResizingArrayStack( void ) :
     N (0),
     max(1) {
     data = new T[1];
     }
     
-template <typename T> ResizingArrayStack<T>::~ResizingArrayStack( void ) {
+template <typename T>
+ResizingArrayStack<T>::~ResizingArrayStack( void ) {
     assert( N == 0 );  // Catch the potential memory leak.
     if ( data )
-        delete data;
+        delete[] data;
     }
 
-template <typename T> void ResizingArrayStack<T>::push( T &item ) {
+template <typename T>
+void ResizingArrayStack<T>::push( T &item ) {
     if ( max == N )
         resize( 2 * max );
     data[N++] = item;
     }
 
-template <typename T> T ResizingArrayStack<T>::pop( void ) {
+template <typename T>
+T ResizingArrayStack<T>::pop( void ) {
     assert( N > 0 );
     T item = data[N-1];
-    data[N-1] = NULL;
     N--;
 
     if ( N <= max/4 )
@@ -39,24 +42,77 @@
     return item;
     }
 
-template <typename T> bool ResizingArrayStack<T>::is_empty( void ) {
+template <typename T>
+bool ResizingArrayStack<T>::is_empty( void ) {
     return N == 0;
     }
 
-template <typename T> size_t ResizingArrayStack<T>::size( void ) {
+template <typename T>
+size_t ResizingArrayStack<T>::size( void ) {
     return N;
     }
 
-template <typename T> void ResizingArrayStack<T>::resize( size_t new_max ) {
+template <typename T>
+void ResizingArrayStack<T>::resize( size_t new_max ) {
     T *new_data = new T[new_max];
     for ( size_t i = 0; i < N; ++i )
         new_data[i] = data[i];
     T *old_data = data;
     data = new_data;
-    delete old_data;
+    delete[] old_data;
     max = new_max;
     }
 
+template <typename T>
+typename ResizingArrayStack<T>::iterator ResizingArrayStack<T>::begin( void ) {
+    return ResizingArrayStack<T>::iterator( data+N-1, data-1 );
+    }
+
+template <typename T>
+typename ResizingArrayStack<T>::iterator ResizingArrayStack<T>::end( void ) {
+    return ResizingArrayStack<T>::iterator( data-1, data-1 );
+    }
+
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <typename T>
+ResizingArrayStack<T>::iterator::iterator( T *c, T *e ) :
+    curr (c),
+    end (e)
+    {
+    }
+
+template <typename T>
+typename ResizingArrayStack<T>::iterator & ResizingArrayStack<T>::iterator::operator++() {
+    if ( this->curr > this->end ) {
+        this->curr -= 1;
+        }
+    return *this;
+    }
+
+template <typename T>
+typename ResizingArrayStack<T>::iterator ResizingArrayStack<T>::iterator::operator++( int ) {
+    auto t = ResizingArrayStack<T>::iterator( *this );
+    if ( this->curr > this->end ) {
+        this->curr -= 1;
+        }
+    return t;
+    }
+
+template <typename T>
+T ResizingArrayStack<T>::iterator::operator*() {
+    return *(this->curr);
+    }
+
+template <typename T>
+bool ResizingArrayStack<T>::iterator::operator!=( typename ResizingArrayStack<T>::iterator ) {
+    return this->curr != this->end;
+    }
+
+
+////////////////////////////////////////////////////////////////////////////////
+
 #ifdef RESIZINGARRAYSTACK_MAIN
 
 #include <iostream>
@@ -74,10 +130,19 @@
 
     std::cout << "Stack has " << stack.size() << " entries." << std::endl;
 
+    for ( auto iter = stack.begin(); iter != stack.end(); ++iter ) {
+        std::cout << *iter << std::endl;
+        }
+
+    std::cout << "Popping entries..." << std::endl;
+
     while ( ! stack.is_empty() ) {
         i = stack.pop();
         std::cout << i << std::endl;
         }
+
+    std::cout << "Stack has " << stack.size() << " entries." << std::endl;
+
     }
 
 #endif
diff -r ca59e5f5b29e -r 310618f5e32a algs4-c++/src/ResizingArrayStack.hpp
--- a/algs4-c++/src/ResizingArrayStack.hpp	Tue May 26 18:18:16 2015 -0500
+++ b/algs4-c++/src/ResizingArrayStack.hpp	Thu May 28 23:53:46 2015 -0500
@@ -17,10 +17,28 @@
     bool is_empty( void );
     size_t size( void );
 
-    // class iterator;
-    // friend class iterator;
-    // class iterator {
-    //     };
+    class iterator;
+    friend class iterator;
+    class iterator {
+
+    public:
+
+        iterator( T *c, T *e );
+
+        iterator& operator++();
+        iterator operator++(int);
+
+        T operator*();
+        bool operator!=( typename ResizingArrayStack<T>::iterator );
+
+    private:
+
+        T *curr;
+        T *end;
+        };
+
+    iterator begin( void );
+    iterator end( void );
 
 private: