C++ Program to implement Dictionary using Hashing

C++ Program to implement Dictionary using Hashing

#include <iostream>

using namespace std;

const int MAX=10;

class dictionary;

class node

{

      string key,value;

      node *next;

public:

      friend class dictionary;

      node()

      {

            next=NULL;

      }

      node(string key,string value)

      {

            this->key=key;

            this->value=value;

            next=NULL;

      }

};

class dictionary

{

      node *head[MAX];

public:

      dictionary()

{

            for(int i=0;i<MAX;i++)

                  head[i]=NULL;

}

      int hashf(string word);

      void insert(string,string);

      void find(string word);

      bool deleteWord(string word);

      void display();

};

int dictionary::hashf(string word)

{

      int asciiSum=0;

      for(int i=0;i<word.length();i++)

      {

            asciiSum=asciiSum+word[i];

      }

      return (asciiSum%10);

}

void dictionary::find(string word)

{

      int index=hashf(word);

      int flag=0;

      node *start=head[index];

      while(start!=NULL)

      {

            if(start->key==word)

            {

                  flag=1;

                  break;

            }

            start=start->next;

      }

      if(flag==1)

            cout<<"Word Is  present.";

      else

            cout<<"Word Is not present.";

}

void dictionary::insert(string word,string meaning)

{

      int index=hashf(word);

      node *p=new node(word,meaning);

      if(head[index]==NULL)

      {

            head[index]=p;

      }

      else

      {

            node *start=head[index];

            while(start->next!=NULL)

                  start=start->next;

            start->next=p;

      }

      cout<<endl<<word<<" inserted into dictionary at index"<<index;

}

bool dictionary::deleteWord(string word)

{

      int index=hashf(word);

      node *tmp=head[index];

      node *par=head[index];

      if(tmp==NULL) //if no word is present at that index

      {

            return false;

      }

      if(tmp->key==word && tmp->next==NULL)//only one word is present

      {

            head[index]=NULL;

            delete tmp;

            return true;

      }

      //tmp=tmp->next;

      while(tmp->key!=word && tmp->next!=NULL)

      {

            par=tmp;

            tmp=tmp->next;

      }

      if(tmp->key==word&&tmp->next!=NULL)
      {
          if(par->key==tmp->key)
          {
              head[index]=tmp->next;
          }
          else
          {
            par->next=tmp->next;
            tmp->next=NULL;
          }
            delete tmp;
            return true;
      }

      else //delete at end

      {

            par->next=NULL;

            tmp->next=NULL;

            delete tmp;

            return true;

      }

      return false;

}

void dictionary:: display()

{

      cout<<"\nIndex\t Key\t Value";

      for(int i=0;i<10;i++)

      {

            node *start=head[i];

            if(start==NULL)

                  cout<<"\n";

            while(start!=NULL)

            {

                  cout<<"\n:"<<i<<"\t"<<start->key <<"\t "<<start->value;

                  start=start->next;

            }

      }

}

int main() {

      dictionary oxford;

      int choice;

      string word,meaning;

      do

      {

            cout<<"\n**** OXFORD DICTIONARY ****\n"

                        <<"1.Insert Word\n"

                        <<"2.Find Word\n"

                        <<"3.Delete Word\n"

                        <<"4.Display\n"

                        <<"Enter Your Choice :";

            cin>>choice;

            switch(choice)

            {

            case 1:

                  cout<<"Enter Word: ";

                  cin>>word;

                  cout<<"Enter Meaning: ";

                  cin>>meaning;

                  oxford.insert(word,meaning);

                  break;

            case 2:

                  cout<<"Enter Word to Search: ";

                  cin>>word;

                  oxford.find(word);

                  break;

            case 3:

                  cout<<"Enter Word to Delete: ";

                  cin>>word;

                  if(oxford.deleteWord(word))

                        cout<<" Word is deleted.";

                  else

                  {

                        cout<<"\nFailed to delete "<<word;

                  }

                  break;

            case 4:

                  cout<<"***Oxford Dictionary***";

                  oxford.display();

                  break;

            default:

                  cout<<"\nWrong Choice.";

            }

      }while(choice!=0);

      return 0;

}

Output: 

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :1

Enter Word: a

Enter Meaning: ant

a inserted into dictionary at index7

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :1

Enter Word: b

Enter Meaning: bat

b inserted into dictionary at index8

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :2

Enter Word to Search: b

Word Is  present.

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :2

Enter Word to Search: c

Word Is not present.

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :4

***Oxford Dictionary***

Index  Key   Value

:7     a      ant

:8     b      bat

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :3

Enter Word to Delete: c

Failed to delete c

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :3

Enter Word to Delete: b

 Word is deleted.

**** OXFORD DICTIONARY ****

1.Insert Word

2.Find Word

3.Delete Word

4.Display

Enter Your Choice :