Solve: maxDepth

Author: daehyun99

maximum-depth-of-binary-tree/daehyun99.py

@@ -0,0 +1,43 @@
+# 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
+class Solution:
+    def maxDepth(self, root: Optional[TreeNode]) -> int:
+        count = 0
+        stacks1 = [root]
+        stacks2= []
+
+        if root is None:
+            return count
+        while len(stacks1) > 0 :
+            count += 1
+            while len(stacks1) > 0 :
+                node = stacks1.pop()
+            
+                if node.left is not None:
+                    stacks2.append(node.left)
+                if node.right is not None:
+                    stacks2.append(node.right)
+            stacks1.extend(stacks2)
+            stacks2 = []
+        return count
+
+"""
+class Solution:
+    def maxDepth(self, root: Optional[TreeNode]) -> int:
+        def depth(node, dep):
+            if (node.left is None) and (node.right is None):
+                return dep
+            if (node.left is not None) and (node.right is None):
+                return depth(node.left, dep+1)
+            if (node.left is None) and (node.right is not None):
+                return depth(node.right, dep+1)
+            else:
+                return max(depth(node.left, dep+1), depth(node.right, dep+1))
+        if root is None:
+            return 0
+        return depth(root, 1)
+"""