list tree problems

Radio stations have a challenging job: Creating a daily play-list. At the beginning of each day, a radio station creates a daily play-list (a list of songs that it will play for that day). If a radio station wishes to stay in business, it will choose the songs that are likely to be most popular. It has been observed that the number of requests for a song in the preceding days is a good predictor of whether the song will be popular in the future. In fact, requests in recent days are better predictors of a song’s popularity than requests in earlier days. For a given song, this observation is modeled by the exponential moving average