Favorite Genres
Given a map Map<String, List<String>> userSongs with user names as keys and a list of all the songs that the user has listened to as values.
Also given a map Map<String, List<String>> songGenres, with song genre as keys and a list of all the songs within that genre as values. The song can only belong to only one genre.
The task is to return a map Map<String, List<String>>, where the key is a user name and the value is a list of the user's favorite genre(s). Favorite genre is the most listened to genre. A user can have more than one favorite genre if he/she has listened to the same number of songs per each of the genres.
Examples
Example 1:
Input:
userSongs = {
"David": ["song1", "song2", "song3", "song4", "song8"],
"Emma": ["song5", "song6", "song7"]
}
songGenres = {
"Rock": ["song1", "song3"],
"Dubstep": ["song7"],
"Techno": ["song2", "song4"],
"Pop": ["song5", "song6"],
"Jazz": ["song8", "song9"]
}
Output:
{
"David": ["Rock", "Techno"],
"Emma": ["Pop"]
}
Explanation:
David has 2 Rock, 2 Techno and 1 Jazz song. So he has 2 favorite genres.
Emma has 2 Pop and 1 Dubstep song. Pop is Emma's favorite genre.
Example 2:
Input:
userSongs = {
"David": ["song1", "song2"],
"Emma": ["song3", "song4"]
},
songGenres = {}
Output:
{
"David": [],
"Emma": []
}