feat: add maximum-depth-of-binary-tree sol

Author: shinsj4653

maximum-depth-of-binary-tree/shinsj4653.py

@@ -1,15 +1,56 @@
 """
 [문제풀이]
 # Inputs
-
+- 이진 트리의 root
 # Outputs
-
+- 가장 최고 깊이
 # Constraints
-
+The number of nodes in the tree is in the range [0, 104].
+-100 <= Node.val <= 100
 # Ideas
+dfs, 즉 재귀 돌면서
+depth 를 max로 업데이트 하면 될 것 같은 느낌?
 
 [회고]
+내 풀이는 정답
+해설 방법도 궁금하여 참고
+-> TC, SC도 파악하는 연습!
+
+TC: o(n)
+SC: o(n)
 
 """
 
+# 내 풀이
+# 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 maxDepth(self, root: Optional[TreeNode]) -> int:
+        def dfs(node, depth):
+            if node is None:
+                return depth - 1
+
+            return max(dfs(node.left, depth + 1), dfs(node.right, depth + 1))
+
+        return dfs(root, 1)
+# 해설
+# bfs 풀이도 존재
+class Solution:
+    def maxDepth(self, root: Optional[TreeNode]) -> int:
+        if not root:
+            return 0
+        max_depth = 0
+        stack = [(root, 1)]
+        while stack:
+            node, depth = stack.pop()
+            max_depth = max(depth, max_depth)
+            if node.left:
+                stack.append((node.left, depth + 1))
+            if node.right:
+                stack.append((node.right, depth + 1))
+        return max_depth
 

merge-two-sorted-lists/shinsj4653.py

@@ -57,4 +57,4 @@ def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) ->
 
         head.next = list1 or list2
         return retList.next
-    
+