A certain Algorithms professor copies the names of the students from class into a Google form for peer-reviews. However, he discovers that somehow one of the students in the class list did not make it into the Google list and he needs to find and resolve the discrepancy.

[a] Write a function missing(class, google) that finds the missing student in (n), i.e. linear time.

[b] Write a function missing(class, google) that finds the missing student in o(n), i.e. better than linear time.