Create 0145-binary-tree-postorder-traversal.py

Author: neetcode-gh

python/0145-binary-tree-postorder-traversal.py

@@ -0,0 +1,19 @@
+class Solution:
+    def postorderTraversal(self, root: Optional[TreeNode]) -> List[int]:
+        stack = [root]
+        visit = [False]
+        res = []
+
+        while stack:
+            cur, v = stack.pop(), visit.pop()
+            if cur:
+                if v:
+                    res.append(cur.val)
+                else:
+                    stack.append(cur)
+                    visit.append(True)
+                    stack.append(cur.right)
+                    visit.append(False)
+                    stack.append(cur.left)
+                    visit.append(False)
+        return res