add maximum depth

Author: LEUNGUU

Diff for: src/linked_list/merge_two_sorted_list.py

@@ -1,12 +1,16 @@
 from typing import Optional
 
+
 class ListNode:
     def __init__(self, val=0, next=None):
         self.val = val
         self.next = next
 
+
 class Solution:
-    def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) -> Optional[ListNode]:
+    def mergeTwoLists(
+        self, list1: Optional[ListNode], list2: Optional[ListNode]
+    ) -> Optional[ListNode]:
         dummy = ListNode()
         tail = dummy
 

Diff for: src/linked_list/reorder_list.py

@@ -1,10 +1,12 @@
 from typing import Optional
 
+
 class ListNode:
     def __init__(self, val=0, next=None):
         self.val = val
         self.next = next
 
+
 class Solution:
     def reorderList(self, head: Optional[ListNode]) -> None:
         """

Diff for: src/linked_list/reverse_linked_list.py

@@ -1,10 +1,12 @@
 from typing import Optional
 
+
 class ListNode:
     def __init__(self, val=0, next=None):
         self.val = val
         self.next = next
 
+
 class Solution:
     def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
         prev, curr = None, head

Diff for: src/trees/max_depth_binary_tree.py

@@ -0,0 +1,47 @@
+from typing import Optional
+from collections import deque
+
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class Solution:
+    def maxDepth_recursive(self, root: Optional[TreeNode]) -> int:
+        if not root:
+            return 0
+        return 1 + max(self.maxDepth(root.left), self.maxDepth(root.right))
+
+    def maxDepth_bfs(self, root: Optional[TreeNode]) -> int:
+        if not root:
+            return 0
+
+        q = deque([root])
+        level = 0
+        while q:
+            current_size = len(q)
+            for _ in range(current_size):
+                node = q.popleft()
+                if node.left:
+                    q.append(node.left)
+                if node.right:
+                    q.append(node.right)
+            level += 1
+        return level
+
+    def maxDepth_dfs(self, root: Optional[TreeNode]) -> int:
+        stack = [[root, 1]]
+        res = 0
+
+        while stack:
+            node, depth = stack.pop()
+
+            if node:
+                res = max(res, depth)
+                stack.append([node.left, depth + 1])
+                stack.append([node.right, depth + 1])
+
+        return res

Diff for: tests/test_time_based_kv_store.py

@@ -23,7 +23,9 @@ def test_time_based_kv_store():
         res = []
         for index in range(op_times):
             if tc["op"][index] == "set":
-                tm.set(tc["value"][index][0], tc["value"][index][1], tc["value"][index][2])
+                tm.set(
+                    tc["value"][index][0], tc["value"][index][1], tc["value"][index][2]
+                )
                 res.append("")
             else:
                 res.append(tm.get(tc["value"][index][0], tc["value"][index][1]))