LeetCode Merge Two Sorted Lists

链接: https://oj.leetcode.com/problems/merge-two-sorted-lists/

题目要去把两个有序的链表合并,并且合并后的链表依然有序.

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution
{
	public:
		ListNode *mergeTwoLists(ListNode *l1,ListNode *l2)
		{
			ListNode *t1=l1; 
			ListNode *t2=l2;
			ListNode *ans=new ListNode(0);	//哨兵
			ListNode *ta=ans;
			while(t1&&t2)
			{
				if(t1->val<t2->val)
				{
					ta->next=t1;	
					t1=t1->next;
					ta->next->next=NULL;
				}
				else
				{
					ta->next=t2;
					t2=t2->next;
					ta->next->next=NULL;
				}
				ta=ta->next;
			}
			if(t1==NULL&&t2!=NULL)
			    ta->next=t2;
			if(t2==NULL&&t1!=NULL)
			    ta->next=t1;
			ans=ans->next;
			return ans;
		}
};