trie in python

python/35_trie/trie.py

@@ -0,0 +1,42 @@
+"""
+    Author: Wenru Dong
+"""
+
+class TrieNode:
+    def __init__(self, data: str):
+        self._data = data
+        self._children = [None] * 26
+        self._is_ending_char = False
+
+
+class Trie:
+    def __init__(self):
+        self._root = TrieNode("/")
+
+    def insert(self, text: str) -> None:
+        node = self._root
+        for index, char in map(lambda x: (ord(x) - ord("a"), x), text):
+            if not node._children[index]:
+                node._children[index] = TrieNode(char)
+            node = node._children[index]
+        node._is_ending_char = True
+
+    def find(self, pattern: str) -> bool:
+        node = self._root
+        for index in map(lambda x: ord(x) - ord("a"), pattern):
+            if not node._children[index]: return False
+            node = node._children[index]
+        return node._is_ending_char
+
+
+if __name__ == "__main__":
+
+    strs = ["how", "hi", "her", "hello", "so", "see"]
+    trie = Trie()
+    for s in strs:
+        trie.insert(s)
+
+    for s in strs:
+        print(trie.find(s))
+
+    print(trie.find("swift"))