Implement Trie (Prefix Tree)
Problem
Implement a trie with insert, search, and startsWith methods.
Example
insert("lintcode")
search("code") // return false
startsWith("lint") // return true
startsWith("linterror") // return false
insert("linterror")
search("lintcode") // return true
startsWith("linterror") // return true
Note
You may assume that all inputs are consist of lowercase letters a-z.
Solution
A typical Trie problem.