#208

Implement Trie (Prefix Tree)

pupil · 565 · lc medium +29 · 69.2% accepted · 12,402 likes · top 77%

Description

A prefix tree (trie, pronounced "try") enables efficient string storage and lookup, powering features like autocomplete and spell-check.

Build the Trie class:

- Trie() sets up an empty trie.

- void insert(String word) stores word in the trie.

- boolean search(String word) returns true if word was previously inserted.

- boolean startsWith(String prefix) returns true if any inserted word begins with prefix.

Example 1:

Input

["Trie", "insert", "search", "search", "startsWith", "insert", "search"]

[[], ["apple"], ["apple"], ["app"], ["app"], ["app"], ["app"]]

Output

[null, null, true, false, true, null, true]

Example 2:

Explanation

Trie trie = new Trie();

trie.insert("apple");

trie.search("apple"); // return True

trie.search("app"); // return False

trie.startsWith("app"); // return True

trie.insert("app");

trie.search("app"); // return True

Code

class Trie:

    def __init__(self):
        

    def insert(self, word: str) -> None:
        

    def search(self, word: str) -> bool:
        

    def startsWith(self, prefix: str) -> bool:
        


# Your Trie object will be instantiated and called as such:
# obj = Trie()
# obj.insert(word)
# param_2 = obj.search(word)
# param_3 = obj.startsWith(prefix)

class Trie:

    def __init__(self):
        

    def insert(self, word: str) -> None:
        

    def search(self, word: str) -> bool:
        

    def startsWith(self, prefix: str) -> bool:
        


# Your Trie object will be instantiated and called as such:
# obj = Trie()
# obj.insert(word)
# param_2 = obj.search(word)
# param_3 = obj.startsWith(prefix)