Create 021. Merge Two Sorted Lists

Author: haibarawu

021. Merge Two Sorted Lists

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+/********************
+// 021. Merge Two Sorted Lists
+// Merge two sorted linked lists and return it as a new list. 
+// The new list should be made by splicing together the nodes of the first two lists.
+// Example:
+// Input: 1->2->4, 1->3->4
+// Output: 1->1->2->3->4->4
+********************/
+
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
+        ListNode head = new ListNode(0);
+        ListNode p = head;
+ 
+        while(l1 != null && l2 != null) {
+            if(l1.val < l2.val) {
+                p.next = l1;
+                l1 = l1.next;
+            }else {
+                p.next = l2;
+                l2 = l2.next;
+            }
+            p = p.next;
+        }
+        
+        if(l1 != null) {
+            p.next = l1;
+        }
+        
+        if(l2 != null) {
+            p.next = l2;
+        }
+ 
+        return head.next;
+    }
+}