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
/**
* 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 *dummy = new ListNode(0);
ListNode *cur = dummy;
while (l1 != NULL && l2 != NULL) {
if (l1 -> val < l2 -> val) {
cur -> next = l1;
l1 = l1 -> next;
}
else {
cur -> next = l2;
l2 = l2 -> next;
}
cur = cur -> next;
}
cur -> next = (l1 != NULL ? l1 : l2);
return dummy -> next;
}
};