// Node.h - letter consists of a plaintext character
//	    plainLeft points to plaintext letter to left
//	    plainRight points to plaintext letter to right
//	    cipher points to cipher char associated with 
//	    current plaintext char
//	    cipherRight points to cipher letter to right
//	    plaintext letters form a circular dll
// 	    cipher letters form a circular singly linked list

#ifndef NODE_CLASS
#define NODE_CLASS

#include <iostream>

class Node {

    char letter;	// plaintext letter
    Node * plainLeft;	// points to previous plaintext letter to left 
    Node * plainRight;	// points to next plaintext letter to right
    Node * cipher;	// points to letter plaintext will be enciphered into
    Node * cipherRight;	// points to next cipher letter

  public:
    // default constructor
    // initializes pointers to NULL
    Node();

    // constructor with plaintext letter x
    // and pl = plainLeft, pr = plainRight
    Node(char x, Node *pl = NULL, Node *pr = NULL);

    // returns the value of the plaintext character
    char getLetter() const;
    
    // returns pointer to node that plainLeft points to
    Node * getPlainLeft() const;
  
    // returns pointer to node that plainRight points to
    Node * getPlainRight() const;
    
    // returns pointer to node that contains corresponding cipher
    Node * getCipher() const;
  
    // returns pointer to node that cipherRight points to
    Node * getCipherRight() const;
    
    // sets the value of the plaintext character to pl
    void setLetter(char pl);
    
    // mutator - changes value of plainLeft to pl
    void setPlainLeft(Node * pl);

    // mutator - changes value of plainRight to pr
    void setPlainRight(Node * pr);
    
    // mutator - changes value of cipher letter to cl
    void setCipher(Node * cl);

    // mutator - changes value of cipherRight to cr
    void setCipherRight(Node * cr);
    
    // writes the contents of a single Node
    // writes the following: cipher = k
    // writes the following: plntxt = f
    void writer() const;
    
  private:

    // YOU MAY ADD ANY OTHER PRIVATE METHODS HERE
};
    
#endif // NODE_CLASS