Week 4: maximum-depth-of-binary-tree solution

Author: mandel-17

maximum-depth-of-binary-tree/mandel-17.py

@@ -0,0 +1,26 @@
+import collections
+from typing import Optional
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+class Solution:
+    def maxDepth(self, root: Optional[TreeNode]) -> int:
+        if root is None:
+            return 0
+        queue = collections.deque([root])
+        depth = 0
+
+        while queue:
+            depth += 1
+            for _ in range(len(queue)):
+                current_root = queue.popleft()
+                if current_root.left:
+                    queue.append(current_root.left)
+                if current_root.right:
+                    queue.append(current_root.right)
+        return depth
+