Create 21-Merge-Two-Sorted-Lists.cs

Author: notauserx

csharp/21-Merge-Two-Sorted-Lists.cs

@@ -0,0 +1,36 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
+public class Solution {
+    public ListNode MergeTwoLists(ListNode list1, ListNode list2) {
+        var dummy = new ListNode();
+        var tail = dummy;
+        
+        while(list1 is not null && list2 is not null) {
+            if(list1.val < list2.val) {
+                tail.next = list1;
+                list1 = list1.next;
+            }
+            else {
+                tail.next = list2;
+                list2 = list2.next;
+            }
+            tail = tail.next;
+        }
+        
+        if(list1 is not null)
+            tail.next = list1;
+        else if(list2 is not null)
+            tail.next = list2;
+        
+        return dummy.next;
+    }
+}