If we consider that the sentiment of a tweet only depends on its content and immediate neighbors, we can leverage a graph-based method for sentiment classification of tweets.
the probability of a tweet belonging to a specific sentiment class can be computed with the following formula: Where c is the sentiment label of a tweet which belongs to {positive, negative, neutral}, G is the tweet graph, N(d) is a specific assignment of sentiment labels to all immediate neighbors of the tweet, and τ is the content of the tweet.