Trie

Implementation in CMU 15-445

• Class Trie with a shared_ptr pointing to TrieNode
• Class TrieNode
  • Contains children_, a map from char to shared_ptr pointing to other TrieNode
  • Class TrieNodeWithValue inherit from TrieNode act as a left node (or terminal node)
    • The value of a key is stored in the node representing the last char of the key.