feat: solve DaleStudy#288 with python

Author: EgonD3V

serialize-and-deserialize-binary-tree/EGON.py

@@ -0,0 +1,65 @@
+from typing import Optional
+
+
+# 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 Codec:
+    """
+    Runtime: 76 ms (Beats 85.72%)
+    Time Complexity: O(n)
+    > dfs를 통해 모든 node를 방문하므로, O(n)
+
+    Memory: 21.40 MB (Beats 12.82%)
+    Space Complexity: O(n)
+    > 일반적인 경우 트리의 깊이만큼 dfs 호출 스택이 쌓이나, 최악의 경우 한쪽으로 편향되었다면 트리의 깊이가 n이 될 수 있으므로 O(n), upper bound
+    """
+
+    def serialize(self, root):
+        """Encodes a tree to a single string.
+
+        :type root: TreeNode
+        :rtype: str
+        """
+
+        def dfs(node: Optional[TreeNode]) -> None:
+            if node is None:
+                result.append("null")
+                return
+            result.append(str(node.val))
+            dfs(node.left)
+            dfs(node.right)
+
+        result = []
+        dfs(root)
+        return ','.join(result)
+
+    def deserialize(self, data):
+        """Decodes your encoded data to tree.
+
+        :type data: str
+        :rtype: TreeNode
+        """
+
+        def dfs() -> Optional[TreeNode]:
+            val = next(values)
+            if val == "null":
+                return None
+            node = TreeNode(int(val))
+            node.left = dfs()
+            node.right = dfs()
+            return node
+
+        values = iter(data.split(','))
+        return dfs()
+
+
+# Your Codec object will be instantiated and called as such:
+# ser = Codec()
+# deser = Codec()
+# ans = deser.deserialize(ser.serialize(root))