1.1 --- a/algs4-c++/src/Stack.cpp	Fri May 29 21:34:18 2015 -0500
     1.2 +++ b/algs4-c++/src/Stack.cpp	Mon Jun 08 17:52:54 2015 -0500
     1.3 @@ -106,6 +106,86 @@
     1.4      return this->curr != other.curr;
     1.5      }
     1.6  
     1.7 +////////////////////////////////////////////////////////////////////////////////
     1.8 +
     1.9 +
    1.10 +#ifdef EXERCISES
    1.11 +
    1.12 +// 1.3.19
    1.13 +// Returns the item if entry was found.  If the entry did not exist, then the returned value is undefined.
    1.14 +template <typename T>
    1.15 +T Stack<T>::delete_bottom( void ) {
    1.16 +    Node *prev, *curr;
    1.17 +    T item;
    1.18 +
    1.19 +    prev = nullptr;
    1.20 +    curr = list;
    1.21 +    if ( curr ) {
    1.22 +        while ( curr->next ) {
    1.23 +            prev = curr;
    1.24 +            curr = curr->next;
    1.25 +            }
    1.26 +
    1.27 +        item = curr->item;
    1.28 +        delete curr;
    1.29 +        if ( prev )
    1.30 +            prev->next = nullptr;
    1.31 +        else
    1.32 +            list = nullptr;
    1.33 +
    1.34 +        N--;
    1.35 +        }
    1.36 +
    1.37 +    return item;
    1.38 +    }
    1.39 +
    1.40 +
    1.41 +// 1.3.20
    1.42 +// Returns the item if entry was found.  If the entry did not exist, then the returned value is undefined.
    1.43 +template <typename T>
    1.44 +T Stack<T>::remove( size_t k ) {
    1.45 +    Node *prev, *curr;
    1.46 +    size_t i=0;
    1.47 +    T item;
    1.48 +
    1.49 +    prev = nullptr;
    1.50 +    curr = list;
    1.51 +    while ( curr && (i < k) ) {
    1.52 +        prev = curr;
    1.53 +        curr = curr->next;
    1.54 +        ++i;
    1.55 +        }
    1.56 +
    1.57 +    if ( curr &&( i == k) ) {
    1.58 +        item = curr->item;
    1.59 +        if ( prev )
    1.60 +            prev->next = curr->next;
    1.61 +        else
    1.62 +            list = curr->next;;
    1.63 +        delete curr;
    1.64 +        N--;
    1.65 +        }
    1.66 +
    1.67 +    return item;
    1.68 +    }
    1.69 +
    1.70 +// 1.3.21
    1.71 +// Returns true if the specified key is in the stack.
    1.72 +template <typename T>
    1.73 +bool Stack<T>::find( T key ) {
    1.74 +    Node *curr = list;
    1.75 +
    1.76 +    while ( curr ) {
    1.77 +        if ( curr->item == key )
    1.78 +            return true;
    1.79 +        curr = curr->next;
    1.80 +        }
    1.81 +
    1.82 +    return false;
    1.83 +    }
    1.84 +
    1.85 +#endif
    1.86 +
    1.87  
    1.88  ////////////////////////////////////////////////////////////////////////////////
    1.89  
    1.90 @@ -130,6 +210,30 @@
    1.91          std::cout << *iter << std::endl;
    1.92          }
    1.93  
    1.94 +#ifdef EXERCISES
    1.95 +    std::cout << "Looking for 3: " << ( stack.find( 3 ) ? "found" : "not found" ) << std::endl;
    1.96 +    std::cout << "Looking for 9999: " << ( stack.find( 9999 ) ? "found" : "not found" ) << std::endl;
    1.97 +
    1.98 +    std::cout << "Removing bottom entry: ";
    1.99 +    i = stack.delete_bottom();
   1.100 +    std::cout << i << std::endl;
   1.101 +    std::cout << "Stack has " << stack.size() << " entries." << std::endl;
   1.102 +
   1.103 +    for ( auto iter = stack.begin(); iter != stack.end(); ++iter ) {
   1.104 +        std::cout << *iter << std::endl;
   1.105 +        }
   1.106 +
   1.107 +    std::cout << "Removing entry 2: ";
   1.108 +    i = stack.remove( 2 );
   1.109 +    std::cout << i << std::endl;
   1.110 +    std::cout << "Stack has " << stack.size() << " entries." << std::endl;
   1.111 +
   1.112 +    for ( auto iter = stack.begin(); iter != stack.end(); ++iter ) {
   1.113 +        std::cout << *iter << std::endl;
   1.114 +        }
   1.115 +
   1.116 +#endif
   1.117 +
   1.118      std::cout << "Popping entries..." << std::endl;
   1.119  
   1.120      while ( ! stack.is_empty() ) {

     2.1 --- a/algs4-c++/src/Stack.hpp	Fri May 29 21:34:18 2015 -0500
     2.2 +++ b/algs4-c++/src/Stack.hpp	Mon Jun 08 17:52:54 2015 -0500
     2.3 @@ -54,6 +54,14 @@
     2.4      iterator begin( void );
     2.5      iterator end( void );
     2.6  
     2.7 +#ifdef EXERCISES
     2.8 +
     2.9 +    T delete_bottom( void );    // 1.3.19
    2.10 +    T remove( size_t k );       // 1.3.20
    2.11 +    bool find( T key );         // 1.3.21
    2.12 +
    2.13 +#endif
    2.14 +
    2.15  private:
    2.16  
    2.17      size_t N;