/*

 * Copyright 2011 Steven Gribble

 *

 *  This file is the solution to an exercise problem posed during

 *  one of the UW CSE 333 lectures (333exercises).

 *

 *  333exercises is free software: you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation, either version 3 of the License, or

 *  (at your option) any later version.

 *

 *  333exercises is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with 333exercises.  If not, see <http://www.gnu.org/licenses/>.

 */



// STL lecture exercise 2



#ifndef _HISTOGRAM_H_

#define _HISTOGRAM_H_



#include <stdint.h>  // for uint32_t

#include <iostream>  // for std::ostream

#include <string>    // for std::string

#include <vector>    // for std::vector

#include <map>       // for std::map

#include <utility>   // for std::pair



using std::string;

using std::ostream;

using std::vector;

using std::pair;

using std::map;



// A Histogram is a class that builds up a histogram of word

// occurrence frequency. Internally, it uses an STL map to store

// a map from word to integer count.

class Histogram {

 public:

  Histogram() { }



  // Add a word occurrence to the histogram.  Converts the word to

  // lowercase before incorporating.

  void AddWord(string word);



  // Return a vector of <word,count> pairs, sorted in descending order

  // of count.

  vector<pair<string, uint32_t> > GetSortedData() const;



  // Override "<<" for std::ostream.

  friend ostream &operator<<(ostream &out, const Histogram &pt);



 private:

  // Disable the copy constructor and assignment operator.

  Histogram(const Histogram &pt);

  Histogram &operator=(const Histogram &pt);



  // Our private member variable storing the histogram data.

  // We use an STL map from word-->count.

  map<string, uint32_t> histogram_data_;

};



#endif  // _HISTOGRAM_H_