ADS Program to create Symbol Table using Hashing

Problem Statement:-

The symbol table is generated by compiler.  From this perspective, the symbol table is a set of name-attribute pairs.  In a symbol table for a compiler, the name is an identifier, and the attributes might include an initial value and a list of lines that use the identifier. Perform the following operations on symbol table:

 (1)   Determine if a particular name is in the table

 (2)   Retrieve the attributes of that name

 (3)   Modify the attributes of that name

 (4)   Insert a new name and its attributes

 (5)   Delete  name and its attribute

Code:-

//============================================================================
// Name        : SymbolTable.cpp
// Author      : 
// Version     :
// Copyright   : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================

#include <iostream>
using namespace std;

const int MAX=100;
class dictionary;
class node
{
 string identifier,scope,type;
 int lineNo;
 node *next;
public:
 friend class SymbolTable;
 node()
 {
  next=NULL;
 }
 node(string key,string value,string type,int lineNo)
 {
  this->identifier=key;
  this->scope=value;
  this->type=type;
  this->lineNo=lineNo;
  next=NULL;
 }
 void print()
 {
  cout<<"\nIdentifier's Name:"<<identifier
    <<"\nType:"<<type
    <<"\nScope: "<<scope
    <<"\nLine Number: "<<lineNo<<endl;
 }
};

class SymbolTable
{
 node *head[MAX];
public:
 SymbolTable()
{
  for(int i=0;i<MAX;i++)
   head[i]=NULL;
}
 int hashf(string id);
 bool insert(string id,string scope,string Type,int lineno);
 string find(string id);
 bool deleteRecord(string id);
 bool modify(string id);
};
bool SymbolTable::modify(string id)
{
 int index=hashf(id);
 //cout<<"\nIndex in find"<<index;
 node *start=head[index];
 if(start==NULL)
  return "-1";
 while(start!=NULL)
 {
  if(start->identifier==id)
  {
    cout<<id<<" is present\n";
    cout<<"Enter Scope: ";
    cin>>(start->scope);
    cout<<"Enter Type: ";
    cin>>(start->type);
    cout<<"Enter Line Number: ";
    cin>>(start->lineNo);
   return true;

  }start=start->next;
 }
 return false;
}
bool SymbolTable::deleteRecord(string id)
{
 int index=hashf(id);
 node *tmp=head[index];
 node *par=head[index];
 if(tmp==NULL) //if no identifier is present at that index
 {
  return false;
 }
 if(tmp->identifier==id && tmp->next==NULL)//only one identifier is present
 {
  tmp->next=NULL;
  delete tmp;
  return true;
 }
 //tmp=tmp->next;
 while(tmp->identifier!=id && tmp->next!=NULL)
 {
  par=tmp;
  tmp=tmp->next;
 }
 if(tmp->identifier==id&&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 SymbolTable::find(string id)
{
 int index=hashf(id);
 //cout<<"\nIndex in find"<<index;
 node *start=head[index];
 if(start==NULL)
  return "-1";
 while(start!=NULL)
 {
  if(start->identifier==id)
  {
   start->print();
   return start->scope;

  }start=start->next;
 }
 return "-1";
}
bool SymbolTable::insert(string id,string scope,string Type,int lineno)
{
 int index=hashf(id);
 node *p=new node(id,scope,Type,lineno);

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

  start->next=p;
  cout<<"\n"<<id<<"inserted. ";
  return true;
 }
 return false;
}
int SymbolTable::hashf(string id)
{
 int asciiSum=0;
 for(int i=0;i<id.length();i++)
 {
  asciiSum=asciiSum+id[i];
 }
 return (asciiSum%100);
}
int main() {
 SymbolTable  st;
  int choice,lineno;
  string id,scope,type;
  do
  {
   cout<<"\n**** SYMBOL_TABLE ****\n"
    <<"1.Insert IDENTIFIER\n"
    <<"2.Find Identifier\n"
    <<"3.Delete identifier\n"
    <<"4.Modify attributes\n"
    <<"Enter Your Choice :";
   cin>>choice;
   switch(choice)
   {
   case 1:
    cout<<"Enter Identifer's Name: ";
    cin>>id;
    cout<<"Enter Scope: ";
    cin>>scope;
    cout<<"Enter Type: ";
    cin>>type;
    cout<<"Enter Line Number: ";
    cin>>lineno;
    if(st.insert(id,scope,type,lineno))
     cout<<endl<<id<<" inserted into Symbol Table.";
    else
     cout<<"\nFailed to insert.";
    break;
   case 2:
    cout<<"Enter Identifier to Search: ";
    cin>>id;
    scope=st.find(id);
    if(scope!="-1")
     cout<<" Identifier Is present.\n";
    else
    {
     cout<<"\n Identifier Not Present";
    }
    break;
   case 3:
    cout<<"Enter Identifier to Delete: ";
    cin>>id;
    if(st.deleteRecord(id))
     cout<<" Identifier's Record is deleted.";
    else
    {
     cout<<"\nFailed to delete "<<id;
    }
    break;
    case 4:
     cout<<"Enter Identifier to Modify: ";
     cin>>id;
     st.modify(id);
     break;
   default:
    cout<<"\nWrong Choice.";
   }

  }while(choice!=0);

 return 0;
}

Output:-