Merge two sorted (ascending) linked lists and return it as a new sorted list. The new sorted list should be made by splicing together the nodes of the two lists and sorted in ascending order.
Example
Given 1->3->8->11->15->null, 2->null , return 1->2->3->8->11->15->null.
思路
我们用谁小谁出列的思路,每次把链表L1和链表L2的两个头的最小值接到新链表的尾部。
Code
/** * Definition for ListNode. * public class ListNode { * int val; * ListNode next; * ListNode(int val) { * this.val = val; * this.next = null; * } * } */ public class Solution { /** * @param ListNode l1 is the head of the linked list * @param ListNode l2 is the head of the linked list * @return: ListNode head of linked list */ public ListNode mergeTwoLists(ListNode l1, ListNode l2) { // write your code here ListNode dummy = new ListNode(0); ListNode curr = dummy; while (l1 != null && l2 != null) { if (l1.val < l2.val) { curr.next = l1; l1 = l1.next; } else { // l1.val >= l2.val curr.next = l2; l2 = l2.next; } curr = curr.next; } if (l1 != null) { curr.next = l1; } if (l2 != null) { curr.next = l2; } return dummy.next; } }