Create 543-Diameter-of-Binary-Tree.py

Author: neetcode-gh

543-Diameter-of-Binary-Tree.py

@@ -0,0 +1,21 @@
+# 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 diameterOfBinaryTree(self, root: TreeNode) -> int:
+        res = [0]
+        
+        def dfs(root):
+            if not root:
+                return -1
+            left = dfs(root.left)
+            right = dfs(root.right)
+            res[0] = max(res[0], 2 + left + right)
+            
+            return 1 + max(left, right)
+        
+        dfs(root)
+        return res[0]