For problems lager than a certain time, the actual time or space required will be less than the Big O multiplied by some constant. ??? ??? ??? binary tree a tree in which each node has at most two children. ??? ??? ??? boxed number a number that is defined as an object, so that it has a runtime type and methods that can be used, e.g. Integer in Java ??? ??? ??? branching factor in a search tree, t