leetcode medium: Implement Trie (Prefix Tree)

https://leetcode.com/problems/implement-trie-prefix-tree/

Implement Trie (Prefix Tree) - LeetCode

 

그냥 트라이를 알고있냐 모르고있냐를 보는거같다.

그렇게 어렵지 않다. 트라이가 뭔지 알고 구현을 한번이라도 해봤으면 금방 푸는 문제.

 

class Node:
    def __init__(self):
        self.next = {}
        self.isWord = False

class Trie:

    def __init__(self):
        self.root = Node()

    def insert(self, word: str) -> None:
        node = self.root
        
        for ch in word:
            if ch not in node.next:
                node.next[ch] = Node()
            node = node.next[ch]
        
        node.isWord = True

    def search(self, word: str) -> bool:
        node = self.root
        
        for ch in word:
            if ch not in node.next:
                return False
            node = node.next[ch]
        
        return node.isWord

    def startsWith(self, prefix: str) -> bool:
        node = self.root
        
        for ch in prefix:
            if ch not in node.next:
                return False
            node = node.next[ch]
            
        return True


# 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)