【LeetCode】21. Merge Two Sorted Lists 解题小结

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 lis

相对还是简单的，直接合并。

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