题目描述:
输入两个递增排序的链表,合并这两个链表并使新链表中的结点仍然是按照递增排序的。
样例
输入:1->3->5 , 2->4->5
输出:1->2->3->4->5->5
分析:
归并排序的合并算法。
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode* merge(ListNode* l1, ListNode* l2) {
ListNode *cur,*p = l1,*q = l2;
ListNode* head = new ListNode(-1);
cur = head;
while(p&&q){
if(p->val < q->val){
cur->next = p;
p = p->next;
cur = cur->next;
}
else{
cur->next = q;
q = q->next;
cur = cur->next;
}
}
if(p) cur->next = p;
if(q) cur->next = q;
return head->next;
}
};