Implement trie prefix tree
July 21, 2022
trie designProblem URL: Implement trie prefix tree
This problem literary ask to implement a prefix tree or Trie. Each node will have children for which we have used a hashmap for constant time insert and lookup abd a boolean value to denote whether it's the end of the word or not.
class TrieNode:
def __init__(self):
self.children = {}
self.end = False
class Trie:
def __init__(self):
self.root = TrieNode()
def insert(self, word: str) -> None:
curr = self.root
for c in word:
if c not in curr.children:
curr.children[c] = TrieNode()
curr = curr.children[c]
curr.end = True
def search(self, word: str) -> bool:
curr = self.root
for c in word:
if c not in curr.children:
return False
curr = curr.children[c]
return curr.end == True
def startsWith(self, prefix: str) -> bool:
curr = self.root
for c in prefix:
if c not in curr.children:
return False
curr = curr.children[c]
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)
Time Complexity: O(n)
Space Complexity: O(n)