// File; ListFunctions.cpp
// Read a file into a vector
// Then, use a functor or two to perform list functions
// Prepared by Dr. Spiegel

#include <iostream>
#include <fstream>
#include <vector>
#include <set>
#include <algorithm>
#include <string>

using namespace std;

// Functor for printing; its state keeps track of items printed
template<class T> struct print : public unary_function<T, void>
{
  print(ostream& out) : os(out), count(0) {}
  void operator() (T x) 
  { os << x << ' '; 
    ++count; 
  }
  ostream& os;
  int count;
};

// Functor for counting occurrences of a letter
template<typename T1> 
  struct countOccurrences : public unary_function<T1, void>
{
  countOccurrences(char key) : count(0), searchKey(key) {}
  void operator() (T1 elt) 
  {  count += ( elt.find(searchKey) < elt.size() ? 1 : 0);
  }
  int count;
  char searchKey;
};

char menu();
void readWords(istream &in,vector<string> &WList);

int main()
{ vector<string> TheWords;
  string fileName;
  cout << "Enter Input File >";
  cin >> fileName;
  ifstream infile(fileName.c_str());
  readWords(infile,TheWords);
  char choice;  
  do {
    choice=toupper(menu());
    if (choice=='P') {
      print<string> P = 
        for_each(TheWords.begin(), TheWords.end(), print<string>(cout));
      cout << endl << P.count << " objects printed." << endl;
    }  
    else if (choice=='F') {
      // This doesn't work! Why not! Hint: Check STL documentation!
      vector<string>::iterator it= max_element(TheWords.begin(),TheWords.end());
      if (it!=TheWords.end())
        cout << "Greatest Word is: " << *it << endl;
    }
    else if (choice=='W') {
      cout << "Words with Letter: Enter Letter >";
      char let;
      cin >> let;
      countOccurrences<string> CO = 
        for_each(TheWords.begin(), TheWords.end(), countOccurrences<string>(let));
      cout << "There were " << CO.count << " words containing " << let << endl;  
    } // else
  } while (toupper(choice)!='Q');
}

char menu()
{ cout << "Choice:\n";
  cout << "P)rint\n";
  cout << "W)ords With a Letter\n";
  cout << "F)ind Last Word Alphabetically\n";
  cout << "Q)uit\n";
  char response;
  cin >> response;
  return(response);
}
 
void readWords(istream &in,vector<string> &WList)
{ string word;
  while (in >> word) 
    WList.push_back(word);
}