source: https://leetcode.com/problems/number-of-music-playlists/ Table of ContentsNumber of Music PlaylistsDescriptionExample 1:Example 2:Example 3:Constraints:Solution Number of Music Playlists Description Your music player contains n different songs. You want to listen to goal songs (not necessarily different) during your trip. To avoid boredom, you will create a playlist so that: Every song is played at least once. A song ...