Create Trie.md

Author: 0xkookoo

docs/Leetcode_Solutions/Python/Summary/Tree/Trie.md

@@ -0,0 +1,45 @@
+```python
+class TrieNode(object):
+
+    def __init__(self):
+        self.children = dict()
+        self.isWordEnd = False
+
+    def buildTrie(self, words):
+        for word in words:
+            curr = self
+            for char in word:
+                if char not in curr.children:
+                    curr.children[char] = TrieNode()
+                curr = curr.children[char]
+            curr.isWordEnd = True
+
+    def find(self, word):
+        curr = self
+        for char in word:
+            if char not in curr.children:
+                return False
+            curr = curr.children[char]
+        return curr.isWordEnd
+
+def print_words(node, word):
+
+    if node.isWordEnd:
+        print(word, end=' ')
+
+    for key, value in node.children.items():
+        print_words(value, word + key)
+
+
+def test():
+    words = ['banana', 'bananas', 'bandana', 'band', 'apple', 'all', 'beast']
+    root = TrieNode()
+    root.buildTrie(words)
+    print_words(root, '')
+    assert root.find('banana')
+    assert not root.find('bandanas')
+    assert not root.find('apps')
+    assert root.find('apple')
+
+test()
+```