104. Maximum Depth of Binary Tree

Author: okyungjin

maximum-depth-of-binary-tree/okyungjin.py

@@ -0,0 +1,28 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+
+# 시간 복잡도: O(N), 모든 노드를 한번 씩 방문
+# 공간 복잡도: O(N), 최악의 경우 모든 노드가 큐에 담길 수 있음
+class Solution:
+    def maxDepth(self, root: Optional[TreeNode]) -> int:
+        if root is None:
+            return 0
+
+        max_depth = 1
+        queue = [(root, 1)]
+
+        while queue:
+            node, cur_depth = queue.pop()
+            max_depth = max(cur_depth, max_depth)
+
+            if node.left:
+                queue.append((node.left, cur_depth + 1))
+
+            if node.right:
+                queue.append((node.right, cur_depth + 1))
+
+        return max_depth