// Example illustrating the use of map STL container
#include <iostream.h>
#include <map.h>
#include <algo.h>
#include <string>

// store phone numbers as a MAP from string --> integer

typedef map<string, long, less<string> > phone_map;
typedef map<string, long, less<string> >::iterator phone_map_ptr;

int main()
{

  phone_map directory;

  directory["Einstein"] = 123456;
  directory["Newton"] = 987654;
  directory["Oppenheimer"] = 45678;
  directory["Fermi"] = 234567;

  // list the directory; map is complicated by the fact
  // that its elements are PAIRS of objects, the first is
  // the key, and the 2nd is the associated value
  // The pairs, fortunately, are represented by the STL
  // template "pair", and there are standard ways to get
  // the first and second element of the pair: using 
  // PUBLIC MEMBER DATA (RATHER THAN FUNCTIONS!!)
  // of "pair" -- "first" and "second" respectively

  phone_map_ptr dp;
  for (dp=directory.begin(); dp!=directory.end(); dp++)
    cout << "Phone number for: " << (*dp).first
	 << " is " << (*dp).second << endl;

  cout << "Map Lookups: " << endl;
  // You can use the subscript notation with maps
  cout << "Phone lookup for Oppenheimer is: " 
       << directory["Oppenheimer"] << endl;

  // dangerous to loop up non existent items!!
  // nonexistent gets inserted in with a "default" value
  cout << "Phone lookup for nonexistent is: " 
       << directory["nonexistent"] << endl;

  for (dp=directory.begin(); dp!=directory.end(); dp++)
    cout << "Phone number for: " << (*dp).first
	 << " is " << (*dp).second << endl;

  // shows how to use the map as a simple database that
  // can be queried...
  string name;
  cout << "Enter name to look for: ";
  cin >> name;
  while (name != "done")
    {
      if (directory.find(name) != directory.end())
	cout << "Phone Number for: " << name << " = "
	     << directory[name] << endl;
      else
	cout << "No Phone Number for: " << name << endl;
      cout << "Enter name to look for: ";
      cin >> name;    
    }  

}