//-----------------------------------------------------------------
//
// templates3.cpp
//
// A template-based stack. This is a template version of the array
// based stack we first encountered back in Unit III.
// 
// written by: Elizabeth Sklar
// modified  : 19th May 2010
//
//-----------------------------------------------------------------

#include <iostream>
#include <cassert>

using namespace std;

// The class definition. 
//
// Note that all the functions are defined inside the class definition.

template <class TYPE>
class stack {
  public:
    explicit stack( int size=100 ) : max_len(size), 
                                     top(EMPTY), 
                                     s(new TYPE[size])
                                     {assert( s != 0 );}
    ~stack() { 
      delete []s; 
    } 

    void reset() { 
      top = EMPTY; 
    }

    void push( TYPE c ) { 
      s[++top] = c; }

    TYPE pop() { 
      return s[top--]; 
    }

    TYPE top_of() const { 
      return s[top]; 
    }

    bool empty() const { 
      return( top == EMPTY ); 
    }

    bool full() const { 
      return( top == max_len - 1 ); 
    }

  private:
    enum { EMPTY = -1 };
    TYPE *s;
    int max_len;
    int top;
};

// A function that uses the stack to reverse an array of characters.

void reverse( char *str[], int n ) {
  stack<char *> stk(n);
  int i;
  for ( i=0; i<n; ++i ) {
    stk.push( str[i] );
  }
  for ( i=0; i<n; ++i ) {
    str[i] = stk.pop();
  }
}

// main has command-line arguments, so you run the
// program like so:
//
// unix-prompt> ./a.out abc def 123

int main( int argc, char *argv[] ) {
  int i;
  cout << "before:\n";
  for ( i=0; i<argc; i++ ) {
    cout << argv[i] << endl;
  }
  reverse( argv, argc );
  cout << "\nafter:\n";
  for ( i=0; i<argc; i++ ) {
    cout << argv[i] << endl;
  }
} // end of main()