/* Code for exercise 5.11. |  | "C++ Solutions--Companion to The C++ Programming Language, Third Edition" | by David Vandevoorde; Addison-Wesley 1998; ISBN 0-201-30965-3. | | Permission to use, copy, modify, distribute and sell this software | and its documentation for any purpose is hereby granted without fee. | The author makes no representations about the suitability of this | software for any purpose.  It is provided "as is" without express or | implied warranty. `----------------------------------------------------------------------*/#include <algorithm>#include <iostream.h>#include <list>#include <set>#include <string>int main() {   using std::copy;   using std::cout;   using std::ostream_iterator;   using std::pair;   using std::string;   typedef std::set<string> WordSet;   typedef WordSet::iterator WordIter;   typedef std::list<WordIter> Index;   WordSet words;   Index input_order;   // Input the words uniquely   for(string new_word;       cin >> new_word, new_word!="Quit";) {      pair<WordIter, bool> const &trace = words.insert(new_word);      if (trace.second)         input_order.push_back(trace.first);   }   // Output unique words in order of input:   cout << "\n>>> Unique words in input order:\n";   for (Index::iterator p = input_order.begin(); p!=input_order.end(); ++p) {      cout << *(*p) << '\n';   }   // Output unique words in default set<string> order:   cout << "\n>>> Unique words in sorted order:\n";   copy(words.begin(), words.end(),        ostream_iterator<string>(cout, "\n"));   return 0;}