// Example program : concordance, using STL container classes
// i.e. for each word, print a list of all pages where it appears
using namespace std;

#include <string>       // the standard string library
#include <iostream>     // for cout
#include <map>
#include <list>

int main(){
  int foo(3);
  {// beginning of block
// create empty concordance:
    map<string, list<int> > concordance;
// add some entries to it:
    concordance["apple"].push_back(foo++);
    concordance["lemon"].push_back(foo++);
    concordance["apple"].push_back(foo++);
    concordance["apple"].push_back(foo++);
    concordance["lemon"].push_back(foo++);
// dump the contents of the concordance:
    for (map<string, list<int> >::const_iterator wordlist = concordance.begin();
                 wordlist != concordance.end(); wordlist++){
// print the word:
      cout << wordlist->first << " : ";
// print the list of all pages where it appears
      for (list<int>::const_iterator page = wordlist->second.begin();
                page != wordlist->second.end(); page++) {
        cout << *page << " ";
      }
      cout << endl;
    }
  }// end of block; all memory used by the concordance has been freed

  // more processing ...
  // and more .....
}