题目:
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.
思路:
从最前面开始比较,每次都是最一开始的进行比较,但要注意比较过程中检查是否有链表已经为空。
代码:
/**
* 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 *dummy=new ListNode(0),*tail=dummy;
while(l1!=NULL&&l2!=NULL){
if(l1->val<l2->val){
tail->next=l1;
l1=l1->next;
}else{
tail->next=l2;
l2=l2->next;
}
tail=tail->next;
}
//检测还有没有剩余
if(l1){
tail->next=l1;
}
if(l2){
tail->next=l2;
}
ListNode *head=dummy->next;
delete dummy;
return head;
}
};