Solve: mergeTwoLists

Author: daehyun99

merge-two-sorted-lists/daehyun99.py

@@ -0,0 +1,25 @@
+# Definition for singly-linked list.
+# 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]:
+        # Space: O(N)
+        # Time: O(N)
+        dummy = ListNode(val=0, next=None)
+        pointer = dummy
+        while (list1 is not None) and (list2 is not None):
+            if list1.val <= list2.val:
+                pointer.next = ListNode(list1.val)
+                list1 = list1.next
+            else:
+                pointer.next = ListNode(list2.val)
+                list2 = list2.next
+            pointer = pointer.next
+        if list1 is not None:
+            pointer.next = list1
+        elif list2 is not None:
+            pointer.next = list2
+
+        return dummy.next