frequencies.cpp

#include <QDebug>

int main(int argc, char** argv) {

  // Original sentence
  QString const sentence = "this test of is a a this test phrase of is a of a of a test";
  qDebug() << "\nTest sentence for histogram is:\n\t" << sentence << "\n\n";

  // Split the sentence
  QStringList const words = sentence.split(" ");

  // Count word frequencies
  QMap<QString, uint> frequencies;
  for(auto w : words) { frequencies[w] += 1; }

  // Copy hash into a sortable container: a list
  typedef QPair<QString,uint> Pair;
  QList<Pair> sortedFrequencies;
  QMapIterator<QString, uint> iter(frequencies);
  while(iter.hasNext()){
    iter.next();
    sortedFrequencies.push_back(Pair(iter.key(),iter.value()));
  }

  // Sort the list by values, descending
  std::sort(sortedFrequencies.begin(), sortedFrequencies.end(), [](Pair const & left_, Pair const & right_ ){
      return left_.second > right_.second;
  });


  // Print out values
  qDebug() << "\nFrequency table of sentence is:\n\n";
  for(auto const value : sortedFrequencies) {
    qDebug() << QString("%1, count = %2")
                    .arg(value.first)
                    .arg(value.second);
  }

  qDebug() << "\nC++ program is DONE.\n";

  return 1;
}