Week 13

Author: 8804who

kth-smallest-element-in-a-bst/8804who.py

@@ -0,0 +1,25 @@
+# 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 kthSmallest(self, root: Optional[TreeNode], k: int) -> int:
+        answer = 0
+
+        def dfs(node):
+            nonlocal k
+            nonlocal answer
+            if node.left:
+                dfs(node.left)
+            k -= 1
+            if k == 0:
+                answer = node.val
+                return
+            if node.right:
+                dfs(node.right)
+        dfs(root)
+
+        return answer
+