ADS Program to create Dictionary ADT Using Hashing

Problem Statement:-

Implement all the functions of a dictionary (ADT) using hashing. Data: Set of (key, value) pairs, Keys are mapped to values, Keys must be comparable, Keys must be unique Standard Operations: Insert(key, value), Find(key), Delete(key)

Code:-

#include <iostream>
using namespace std;

const int MAX=100;
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);
 bool insert(string,string);
 string find(string word);
 bool deleteWord(string word);
};
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
 {
  tmp->next=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)
 {
  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;
}
string dictionary::find(string word)
{
 int index=hashf(word);
 //cout<<"\nIndex in find"<<index;
 node *start=head[index];
 if(start==NULL)
  return "-1";
 while(start!=NULL)
 {
  if(start->key==word)
   return start->value;
  start=start->next;
 }
 return "-1";
}
bool dictionary::insert(string word,string meaning)
{
 int index=hashf(word);
 node *p=new node(word,meaning);

 if(head[index]==NULL)
 {
  head[index]=p;
  cout<<"\n"<<word<<"inserted. ";
  return true;
 }
 else
 {
  node *start=head[index];
  while(start->next!=NULL)
   start=start->next;

  start->next=p;
  cout<<"\n"<<word<<"inserted. ";
  return true;
 }
 return false;
}
int dictionary::hashf(string word)
{
 int asciiSum=0;
 for(int i=0;i<word.length();i++)
 {
  asciiSum=asciiSum+word[i];
 }
 return (asciiSum%100);
}
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"
   <<"Enter Your Choice :";
  cin>>choice;
  switch(choice)
  {
  case 1:
   cout<<"Enter Word: ";
   cin>>word;
   cout<<"Enter Meaning: ";
   cin>>meaning;
   if(oxford.insert(word,meaning))
    cout<<endl<<word<<" inserted into dictionary.";
   else
    cout<<"\nFailed to insert.";
   break;
  case 2:
   cout<<"Enter Word to Search: ";
   cin>>word;
   meaning=oxford.find(word);
   if(meaning!="-1")
    cout<<" Word Is present.\n"<<word<<" = "<<meaning ;
   else
   {
    cout<<"\n Word Not Present";
   }
   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;
  default:
   cout<<"\nWrong Choice.";
  }

 }while(choice!=0);

 return 0;
}

Output:-