Tjuyy's Blog

class TrieNode(object):
    def __init__(self):
        self.children = [None]*26
        self.isEnd = False

class Trie(object):

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.root = TrieNode()

    def insert(self, word):
        """
        Inserts a word into the trie.
        :type word: str
        :rtype: None
        """
        cur = self.root
        for char in word:
            if cur.children[ord(char) - ord('a')] is None:
                cur.children[ord(char) - ord('a')] = TrieNode()
            cur = cur.children[ord(char) - ord('a')]
        cur.isEnd = True

    def search(self, word):
        """
        Returns if the word is in the trie.
        :type word: str
        :rtype: bool
        """
        cur = self.root
        for char in word:
            if cur.children[ord(char) - ord('a')]:
                cur = cur.children[ord(char) - ord('a')]
            else:
                return False
        return cur is not None and cur.isEnd

    def startsWith(self, prefix):
        """
        Returns if there is any word in the trie that starts with the given prefix.
        :type prefix: str
        :rtype: bool
        """
        cur = self.root
        for char in prefix:
            if cur.children[ord(char) - ord('a')]:
                cur = cur.children[ord(char) - ord('a')]
            else:
                return False
        return cur is not None


# 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):
        """
        Initialize your data structure here.
        """
        self.trie = {}

    def insert(self, word: str) -> None:
        """
        Inserts a word into the trie.
        """
        trie = self.trie
        for ch in word:
            if ch not in trie:
                trie[ch] = {}
            trie = trie[ch]
        trie['end'] = True
        
    def search(self, word: str) -> bool:
        """
        Returns if the word is in the trie.
        """
        trie = self.trie
        for ch in word:
            if ch in trie:
                trie = trie[ch]
            else:
                return False
        return 'end' in trie

    def startsWith(self, prefix: str) -> bool:
        """
        Returns if there is any word in the trie that starts with the given prefix.
        """
        trie = self.trie
        for ch in prefix:
            if ch in trie:
                trie = trie[ch]
            else:
                return False
        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)