Use Java, Standard Input Output

Digest Recommendation Problem ID: digest Quora's mission is to share and grow the world's knowledge. A vast amount of the knowledge that would be valu- able to many people is currently only available to a few - either locked in people's heads, or only accessible to select groups. We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge for the benefit of the rest of the world. There's a lot of content on Quora and we need a way of recommending the top stories for a user. Recommender systems drive many features at Quora, but in this problem we'll focus on Digest recommendation. Quora Digests are emails which we send to users containing top recommended stories based on their interests. Note: This is a fictitious representation of our Digest recommender system. There are n stories (S1, ..., Sn) and m users (U1,...,Um). Each story is created by a single user. A user can follow both other users and other stories. The Digest recommendation score for story Sk to user U; is defined as follows: If U; created or follows Sk, the score is -1. . Otherwise, the score is a(U,U;) b(U;, Sk) j=1 m Digest Recommendation Problem ID: digest Quora's mission is to share and grow the world's knowledge. A vast amount of the knowledge that would be valu- able to many people is currently only available to a few - either locked in people's heads, or only accessible to select groups. We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge for the benefit of the rest of the world. There's a lot of content on Quora and we need a way of recommending the top stories for a user. Recommender systems drive many features at Quora, but in this problem we'll focus on Digest recommendation. Quora Digests are emails which we send to users containing top recommended stories based on their interests. Note: This is a fictitious representation of our Digest recommender system. There are n stories (S1, ..., Sn) and m users (U1,...,Um). Each story is created by a single user. A user can follow both other users and other stories. The Digest recommendation score for story Sk to user U; is defined as follows: If U; created or follows Sk, the score is -1. . Otherwise, the score is a(U,U;) b(U;, Sk) j=1 m