1.1 --- a/algs4-c++/src/ResizingArrayStack.cpp	Tue May 26 18:18:16 2015 -0500
     1.2 +++ b/algs4-c++/src/ResizingArrayStack.cpp	Thu May 28 23:53:46 2015 -0500
     1.3 @@ -1,5 +1,5 @@
     1.4 -// g++ -std=c++0x ResizingArrayStack.cpp
     1.5 -// g++ -std=c++11 ResizingArrayStack.cpp
     1.6 +// g++ -D RESIZINGARRAYSTACK_MAIN -std=c++0x ResizingArrayStack.cpp
     1.7 +// g++ -D RESIZINGARRAYSTACK_MAIN -std=c++11 ResizingArrayStack.cpp
     1.8  
     1.9  
    1.10  #include "ResizingArrayStack.hpp"
    1.11 @@ -9,28 +9,31 @@
    1.12  
    1.13  #include <iostream>
    1.14  
    1.15 -template <typename T> ResizingArrayStack<T>::ResizingArrayStack( void ) :
    1.16 +template <typename T>
    1.17 +ResizingArrayStack<T>::ResizingArrayStack( void ) :
    1.18      N (0),
    1.19      max(1) {
    1.20      data = new T[1];
    1.21      }
    1.22      
    1.23 -template <typename T> ResizingArrayStack<T>::~ResizingArrayStack( void ) {
    1.24 +template <typename T>
    1.25 +ResizingArrayStack<T>::~ResizingArrayStack( void ) {
    1.26      assert( N == 0 );  // Catch the potential memory leak.
    1.27      if ( data )
    1.28 -        delete data;
    1.29 +        delete[] data;
    1.30      }
    1.31  
    1.32 -template <typename T> void ResizingArrayStack<T>::push( T &item ) {
    1.33 +template <typename T>
    1.34 +void ResizingArrayStack<T>::push( T &item ) {
    1.35      if ( max == N )
    1.36          resize( 2 * max );
    1.37      data[N++] = item;
    1.38      }
    1.39  
    1.40 -template <typename T> T ResizingArrayStack<T>::pop( void ) {
    1.41 +template <typename T>
    1.42 +T ResizingArrayStack<T>::pop( void ) {
    1.43      assert( N > 0 );
    1.44      T item = data[N-1];
    1.45 -    data[N-1] = NULL;
    1.46      N--;
    1.47  
    1.48      if ( N <= max/4 )
    1.49 @@ -39,24 +42,77 @@
    1.50      return item;
    1.51      }
    1.52  
    1.53 -template <typename T> bool ResizingArrayStack<T>::is_empty( void ) {
    1.54 +template <typename T>
    1.55 +bool ResizingArrayStack<T>::is_empty( void ) {
    1.56      return N == 0;
    1.57      }
    1.58  
    1.59 -template <typename T> size_t ResizingArrayStack<T>::size( void ) {
    1.60 +template <typename T>
    1.61 +size_t ResizingArrayStack<T>::size( void ) {
    1.62      return N;
    1.63      }
    1.64  
    1.65 -template <typename T> void ResizingArrayStack<T>::resize( size_t new_max ) {
    1.66 +template <typename T>
    1.67 +void ResizingArrayStack<T>::resize( size_t new_max ) {
    1.68      T *new_data = new T[new_max];
    1.69      for ( size_t i = 0; i < N; ++i )
    1.70          new_data[i] = data[i];
    1.71      T *old_data = data;
    1.72      data = new_data;
    1.73 -    delete old_data;
    1.74 +    delete[] old_data;
    1.75      max = new_max;
    1.76      }
    1.77  
    1.78 +template <typename T>
    1.79 +typename ResizingArrayStack<T>::iterator ResizingArrayStack<T>::begin( void ) {
    1.80 +    return ResizingArrayStack<T>::iterator( data+N-1, data-1 );
    1.81 +    }
    1.82 +
    1.83 +template <typename T>
    1.84 +typename ResizingArrayStack<T>::iterator ResizingArrayStack<T>::end( void ) {
    1.85 +    return ResizingArrayStack<T>::iterator( data-1, data-1 );
    1.86 +    }
    1.87 +
    1.88 +
    1.89 +////////////////////////////////////////////////////////////////////////////////
    1.90 +
    1.91 +template <typename T>
    1.92 +ResizingArrayStack<T>::iterator::iterator( T *c, T *e ) :
    1.93 +    curr (c),
    1.94 +    end (e)
    1.95 +    {
    1.96 +    }
    1.97 +
    1.98 +template <typename T>
    1.99 +typename ResizingArrayStack<T>::iterator & ResizingArrayStack<T>::iterator::operator++() {
   1.100 +    if ( this->curr > this->end ) {
   1.101 +        this->curr -= 1;
   1.102 +        }
   1.103 +    return *this;
   1.104 +    }
   1.105 +
   1.106 +template <typename T>
   1.107 +typename ResizingArrayStack<T>::iterator ResizingArrayStack<T>::iterator::operator++( int ) {
   1.108 +    auto t = ResizingArrayStack<T>::iterator( *this );
   1.109 +    if ( this->curr > this->end ) {
   1.110 +        this->curr -= 1;
   1.111 +        }
   1.112 +    return t;
   1.113 +    }
   1.114 +
   1.115 +template <typename T>
   1.116 +T ResizingArrayStack<T>::iterator::operator*() {
   1.117 +    return *(this->curr);
   1.118 +    }
   1.119 +
   1.120 +template <typename T>
   1.121 +bool ResizingArrayStack<T>::iterator::operator!=( typename ResizingArrayStack<T>::iterator ) {
   1.122 +    return this->curr != this->end;
   1.123 +    }
   1.124 +
   1.125 +
   1.126 +////////////////////////////////////////////////////////////////////////////////
   1.127 +
   1.128  #ifdef RESIZINGARRAYSTACK_MAIN
   1.129  
   1.130  #include <iostream>
   1.131 @@ -74,10 +130,19 @@
   1.132  
   1.133      std::cout << "Stack has " << stack.size() << " entries." << std::endl;
   1.134  
   1.135 +    for ( auto iter = stack.begin(); iter != stack.end(); ++iter ) {
   1.136 +        std::cout << *iter << std::endl;
   1.137 +        }
   1.138 +
   1.139 +    std::cout << "Popping entries..." << std::endl;
   1.140 +
   1.141      while ( ! stack.is_empty() ) {
   1.142          i = stack.pop();
   1.143          std::cout << i << std::endl;
   1.144          }
   1.145 +
   1.146 +    std::cout << "Stack has " << stack.size() << " entries." << std::endl;
   1.147 +
   1.148      }
   1.149  
   1.150  #endif

     2.1 --- a/algs4-c++/src/ResizingArrayStack.hpp	Tue May 26 18:18:16 2015 -0500
     2.2 +++ b/algs4-c++/src/ResizingArrayStack.hpp	Thu May 28 23:53:46 2015 -0500
     2.3 @@ -17,10 +17,28 @@
     2.4      bool is_empty( void );
     2.5      size_t size( void );
     2.6  
     2.7 -    // class iterator;
     2.8 -    // friend class iterator;
     2.9 -    // class iterator {
    2.10 -    //     };
    2.11 +    class iterator;
    2.12 +    friend class iterator;
    2.13 +    class iterator {
    2.14 +
    2.15 +    public:
    2.16 +
    2.17 +        iterator( T *c, T *e );
    2.18 +
    2.19 +        iterator& operator++();
    2.20 +        iterator operator++(int);
    2.21 +
    2.22 +        T operator*();
    2.23 +        bool operator!=( typename ResizingArrayStack<T>::iterator );
    2.24 +
    2.25 +    private:
    2.26 +
    2.27 +        T *curr;
    2.28 +        T *end;
    2.29 +        };
    2.30 +
    2.31 +    iterator begin( void );
    2.32 +    iterator end( void );
    2.33  
    2.34  private:
    2.35