#include <iostream>
#include <string>
#include <map>

using std::map;
using std::cout;
using std::endl;

typedef std::string Word;

int main() {

   Word w1 = "Apple", w2 = "Peach", w3 = "Banana", w4 = "Orange";

   map< Word, int > m;

   // to add a "pair" to a map use the make_pair function along
   // with the map insert member function:

   m.insert( make_pair( w1, 1 ) );
   m.insert( make_pair( w4, 4 ) );
   m.insert( make_pair( w2, 2 ) );
   m.insert( make_pair( w3, 3 ) );

   // be careful and make sure that the arguments you pass to make_pair
   //  are of the same type that the map contains - in this case <Word,int>
   // the first item of the pair is the KEY (aka index) that will be used
   // to find the second item of the pair (the data value)

   // you can then treat the map like an array and use the KEY to find
   // the data value (aka element) that is paired (associated) with that key

   cout << m[ "Apple" ] << endl;  // should output 1
   cout << m[ "Peach" ] << endl;    // should output 2
   cout << m[ "Banana" ] << endl;   // should output 3
   cout << m[ w4 ] << endl;       // should output 4

   m[ "Orange" ] = 100;  // m[ KEY ] returns the item (by reference) paired
                         //   with that KEY and in this case modifies it.

   cout << m[ w4 ] << endl;        // should output 100

   m[ w4 ] = 4;

   cout << "-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*" << endl;

   // using an iterator on a map:
   // m.begin() returns an iterator to the first element of the map IN
   //     SORTED ORDER!
   // m.end() returns an iterator to the element AFTER the last one
   //     in the map
   //
   // also the iterator *points* to a special object a first and a second
   // field which can be accessed as below, the first field is the PAIR key
   // and the second field is the PAIR value.
   //
   // the way that a map works internally is that it creates a BST to
   // store the items "sorted" by their KEY - the Key type used must
   // support the < and == operators otherwise it won't compile

   map< Word, int >::const_iterator i;

   for ( i = m.begin(); i != m.end(); i++ )
      cout << i->first << " " << i->second << endl;
      // prints the key and value pair

   // the above for loop will print out the fruit in alphabetic order

   cout << "-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*" << endl;

   cout << "The size of m is: " << m.size() << endl;  // should be 4
   cout << " and thus m is obviously";

   if ( m.empty() )
      cout << " empty." << endl;
   else
      cout << " not empty." << endl;

   m.clear(); // removes all of the elements of the map

   cout << endl << "The size of m is: " << m.size() << endl;
   cout << " and thus m is obviously";

   if ( m.empty() )
      cout << " empty." << endl;
   else
      cout << " not empty." << endl;

   m[ "FOO" ] = 3;  // amazingly (and dangerously) it creates a pair
                    // if the KEY doesn't exist

   cout << endl << "The size of m is: " << m.size() << endl;
   cout << " and thus m is obviously";

   if ( m.empty() )
      cout << " empty." << endl;
   else
      cout << " not empty." << endl;

   cout << endl << endl;

   return 0;

}