What is the author's style in Suzanne's Diary for Nicholas by James Patterson?

There are three points of view in the book. When Katie is the section title, the story is from Katie's point of view. When The Diary is the section heading, we have Suzanne's point of view. Matt's point of view happens only once. Matt has one section in the diary which is entitled Matthew. Matt tells of Nicky's death. The whole book is basically the story of two women. Matt's new love and Matt's first love.