Albus Dumbledore

Professor Albus Percival Wulfric Brian Dumbledore is a fictional character in J. K. Rowling's Harry Potter series. For most of the series, he is the headmaster of the wizarding school Hogwarts. As part of his backstory, it is revealed that he is the founder and leader of the Order of the Phoenix, an organisation dedicated to fighting Lord Voldemort.

Dumbledore is portrayed by Richard Harris in the film adaptations of Harry Potter and the Philosopher's Stone and Harry Potter and the Chamber of Secrets. After Harris' death, Michael Gambon portrayed Dumbledore for all of the remaining films.

Rowling stated she chose the name Dumbledore, which is an Early Modern English word for "bumblebee", because of Dumbledore's love of music: she imagined him walking around "humming to himself a lot".

Character development

The author has stated that she enjoys writing Dumbledore because he "is the epitome of goodness." Rowling said that Dumbledore speaks for her, as he "knows pretty much everything" about the Harry Potter universe. Rowling mentioned that Dumbledore regrets "that he has always had to be the one who knew, and who had the burden of knowing. And he would rather not know." As a mentor to the central character Harry Potter, "Dumbledore is a very wise man who knows that Harry is going to have to learn a few hard lessons to prepare him for what may be coming in his life. He allows Harry to get into what he wouldn't allow another pupil to do, and he also unwillingly permits Harry to confront things he’d rather protect him from." In a 1999 interview, Rowling stated that she imagined Dumbledore "more as a John Gielgud type, you know, quite elderly and – and quite stately." During his time as a student, Dumbledore was in Gryffindor House. Rowling said in an interview that Dumbledore was about 150 years old. However, on her website, she states that Dumbledore was born in 1881, making him either 115 or 116 when he died.

Harry Potter

Harry Potter is a series of seven fantasy novels and one play written by British author J. K. Rowling. The series chronicles the life of a young wizard, Harry Potter, and his friends Hermione Granger and Ron Weasley, all of whom are students at Hogwarts School of Witchcraft and Wizardry. The main story arc concerns Harry's struggle against the Dark wizard Lord Voldemort, who aims to become immortal, overthrow the Ministry of Magic, subjugate non-magic people and destroy anyone who stands in his way.

Since the release of the first novel, Harry Potter and the Philosopher's Stone, on 30 June 1997, the books have gained immense popularity, critical acclaim and commercial success worldwide. They attracted a wide adult audience, and have remained one of the preeminent cornerstones of young adult literature. The series has also had some share of criticism, including concern about the increasingly dark tone as the series progressed, as well as the often gruesome and graphic violence depicted in the series. As of July 2013, the books have sold more than 450 million copies worldwide, making the series the best-selling book series in history, and have been translated into 73 languages. The last four books consecutively set records as the fastest-selling books in history, with the final instalment selling roughly 11 million copies in the United States within the first 24 hours of its release.

Order of the Phoenix

Order of the Phoenix may refer to:

Big O notation

In mathematics, big O notation describes the limiting behavior of a function when the argument tends towards a particular value or infinity, usually in terms of simpler functions. It is a member of a larger family of notations that is called Landau notation, Bachmann–Landau notation (after Edmund Landau and Paul Bachmann), or asymptotic notation. In computer science, big O notation is used to classify algorithms by how they respond (e.g., in their processing time or working space requirements) to changes in input size. In analytic number theory, it is used to estimate the "error committed" while replacing the asymptotic size, or asymptotic mean size, of an arithmetical function, by the value, or mean value, it takes at a large finite argument. A famous example is the problem of estimating the remainder term in the prime number theorem.

Big O notation characterizes functions according to their growth rates: different functions with the same growth rate may be represented using the same O notation.