leetcode.com 426. Convert Binary Search Tree to Sorted Doubly Linked List

문제 링크: https://leetcode.com/problems/convert-binary-search-tree-to-sorted-doubly-linked-list/

Author: skysign

leetcode.com 426. Convert Binary Search Tree to Sorted Doubly Linked List [Premium]/main.py

@@ -0,0 +1,61 @@
+# Definition for a Node.
+from typing import Optional, List
+
+
+class Node:
+    def __init__(self, val, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class Solution:
+    def __init__(self):
+        self.root: Optional[Node] = None
+        self.prev: Optional[Node] = None
+        self.list: List[Optional[Node]] = []
+
+    def treeToDoublyList(self, root: Optional[Node]) -> Optional[Node]:
+        if not root:
+            return None
+
+        self.inorder(root)
+
+        for node in self.list:
+            self.visit(node)
+
+        return self.root
+
+    def append(self, node: Optional[Node]):
+        self.list.append(node)
+        print(node.val)
+
+    def visit(self, node: Optional[Node]):
+        if not self.root:
+            self.root = node
+            self.prev = node
+            self.prev.left = node
+            self.prev.right = node
+        else:
+            if self.root == self.prev:
+                self.prev.right = node
+                self.prev.left = node
+                node.left = self.prev
+                node.right = self.prev
+                self.prev = node
+            else:
+                self.prev.right = node
+                node.left = self.prev
+                node.right = self.root
+                self.root.left = node
+                self.prev = node
+
+
+    def inorder(self, node: Optional[Node]):
+        if node.left:
+            self.inorder(node.left)
+
+        self.append(node)
+
+        if node.right:
+            self.inorder(node.right)

leetcode.com 426. Convert Binary Search Tree to Sorted Doubly Linked List [Premium]/test_main.py

@@ -0,0 +1,14 @@
+from unittest import TestCase
+from main import Solution, Node
+
+class TestSolution(TestCase):
+    def test1_tree_to_doubly_list(self):
+        sol = Solution()
+        node1 = Node(1)
+        node3 = Node(3)
+        node2 = Node(2, node1, node3)
+        node5 = Node(5)
+        node4 = Node(4, node2, node5)
+        answer = sol.treeToDoublyList(node4)
+        print(answer.val)
+        self.assertEqual(0, 0)