merge two sorted lists solution

Author: parkhojeong

merge-two-sorted-lists/parkhojeong.py

@@ -0,0 +1,35 @@
+# 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]:
+        if not list1:
+            return list2
+        if not list2:
+            return list1
+
+
+        if list1.val > list2.val:
+            list1, list2 = list2, list1
+
+        head = list1
+
+        while list1 and list2:
+            if not list1.next:
+                list1.next = list2
+                break
+
+
+            if list2.val <= list1.next.val:
+                list2_next = list2.next
+
+                list2.next = list1.next
+                list1.next = list2
+                list2 = list2_next
+            else:
+                list1 = list1.next
+
+
+        return head