01
04/2015
[LeetCode] Merge Two Sorted Lists
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.
解题思路：
这道题是我做的leetcode最容易的题目了。其中有个小技巧，就是在最开始的时候申请一个头结点，然后在融合之后再删除头结点。这样能够让代码更加清晰。利用原有的空间，更加加快了效率，在leetcode跑的时间仅仅13ms。Talk is cheap, show you the cade:
/**
* 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* head=new ListNode(0);
ListNode* p = head; //指向融合的最后一个元素
while(l1!=NULL&&l2!=NULL){
if(l1->val<l2->val){
p->next=l1;
p=l1;
l1=l1->next;
}else{
p->next=l2;
p=l2;
l2=l2->next;
}
}
while(l1!=NULL){
p->next=l1;
p=l1;
l1=l1->next;
}
while(l2!=NULL){
p->next=l2;
p=l2;
l2=l2->next;
}
p->next = NULL;
p=head;
head=head->next;
delete p;
return head;
}
};
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