Merge pull request #835 from changchanghwang/main

[Arthur] week 4

Author: changchanghwang

merge-two-sorted-lists/changchanghwang.go

@@ -0,0 +1,20 @@
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+func mergeTwoLists(list1 *ListNode, list2 *ListNode) *ListNode {
+	if list1 == nil {
+		return list2
+	}
+	if list2 == nil {
+		return list1
+	}
+
+	if list1.Val < list2.Val {
+		list1.Next = mergeTwoLists(list1.Next, list2)
+		return list1
+	}
+	list2.Next = mergeTwoLists(list1, list2.Next)
+	return list2
+}