【LeetCode】-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.

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { *         val = x; *         next = null; *     } * } */public class Solution {    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {         ListNode head = new ListNode(0);        ListNode tail = head;        while( l1!=null && l2!=null ){        if( l1.val<l2.val ){        tail.next = l1;        tail = tail.next;        l1 = l1.next;        }else{        tail.next = l2;        tail = tail.next;        l2 = l2.next;        }        }        if( l1!=null ){        tail.next = l1;        }else if(l2!=null){        tail.next = l2;        }        return head.next;        }}