[chordpli] WEEK 04 solutions (#1832)

Author: chordpli

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

@@ -0,0 +1,9 @@
+class Solution:
+    def maxDepth(self, root: Optional[TreeNode]) -> int:
+        if not root:
+            return 0
+
+        right = self.maxDepth(root.right)
+        left = self.maxDepth(root.left)
+
+        return max(right, left) + 1

merge-two-sorted-lists/chordpli.py

@@ -0,0 +1,29 @@
+# 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]:
+        if not list1:
+            return list2
+
+        if not list2:
+            return list1
+
+        merge_node: ListNode = ListNode()
+        current = merge_node
+
+        while list1 and list2:
+            if list1.val < list2.val:
+                current.next = list1
+                list1 = list1.next
+            else:
+                current.next = list2
+                list2 = list2.next
+
+            current = current.next
+
+        current.next = list1 or list2
+        return merge_node.next