LeetCode 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.

题意：将两个有序的链表合并成一个链表

思路：每次比较链表头就行了，把比较小的插入新的链表中

/**
 * 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(0);
        ListNode *cur = &head;
        
        while (l1 != NULL && l2 != NULL) {
            ListNode *tmp;
            if (l1->val < l2->val) {
                tmp = l1;
                l1 = l1->next;
            } else {
                tmp = l2;
                l2 = l2->next;
            }
            cur->next = tmp;
            cur = cur->next;
        }
        if (l1 != NULL) cur->next = l1;
        if (l2 != NULL) cur->next = l2; 
        if (l1 == NULL && l2 == NULL) 
            cur->next = NULL;
        return head.next;
    }
};

LeetCode Merge Two Sorted Lists

原文：http://blog.csdn.net/u011345136/article/details/43703341