public:
  spellChecker() {
    wordList=NULL;
  }
 
  void addWord(char* aWord) {
    int word_size=strlen(aWord) + 1;
    char* dest=new char[word_size];
 
    strcpy(dest,aWord);
    wordRecord* newRec=new wordRecord;
	newRec -> word=dest;
	newRec -> next=wordList;
	wordList=newRec;
  }
 
  void printDict() {
	wordRecord* wordPointer = wordList;
    while(wordPointer != NULL) {
    	printf("%s\n", wordPointer -> word);
    	wordPointer = wordPointer -> next;   
    }
  }
  public override bool isKnownWord() { // needs to be abstract and overridable
  }
};

int main() {
  char* words[] = {(char*)"hello", (char*)"Womble", (char*)"goodbye"};
 
  char inputWord[80];
 
  spellChecker * sc = new caseSensitiveSpellChecker();
 
  for (int i=0; i<sizeof(words)/sizeof(char*); i++)  sc->addWord(words[i]);
 
  printf("Case sensitive dictionary contents:\n");
  sc->printDict();
 
  printf("Enter word ('END' to end):  ");
  scanf("%s", inputWord);
 
  while (strcmp(inputWord, "END")) {
    if (sc->isKnownWord(inputWord)) printf("yes\n");
    else printf("no\n");
    printf("Enter word ('END' to end):  ");
    scanf("%s", inputWord);
  }
 
  delete sc;
 
}

class Greeting
  {
  public:
    // Here is our abstract, overridable method
    virtual std::string hello() const = 0;
  };
 
// Here is an example of how it is used
class Saludo: public Greeting
  {
  public:
    std::string hello() const { return std::string("Buenos Dias"); }
  };

    public:
        virtual bool isKnownWord(){};

class Base
{
    public:
        virtual bool isKnownWord(){};
};

#include "Base.h"
class Derived:public Base
{
    public:
        virtual bool isKnownWord();
};

#include "Derived.h"
 
bool Derived::isKnownWord()
{
     // your overridden code here
}

virtual bool isKnownWord() override;