Learn/C++/C++ Beginner/Collections: vector, map, set/Checkpoint: Collections/Word FrequencyWord FrequencyChallenge on lesson: Checkpoint: CollectionsInstructionsCodeOutputImplement word_freq(text) returning a std::map<std::string,int> counting lowercase space-separated words, and most_common(freq) returning the alphabetically-first among the most frequent.Difficulty: beginnerSubmitPress Submit to check your solution.Back to lesson: Checkpoint: Collections