National Olympiad in Informatics in provinces (abbr. NOIp) is an informatics competition which is held from 1995 for Chinese secondary school students (including Hong Kong and Macao). The competitors will be divided in 2 groups. The junior group is mainly for junior high school students, and the senior group is mainly for senior high school students. The preliminary is a paper-based theory test. Only the top 10%~15% of the competitors will be able to attend the final. The final is computer-based programming test. For the senior group before 2011 and the junior group, the final was held in a single day with 4 problems for competitors to solve. From 2011, it is held in the whole weekend with 3 problems each day for senior group.