[leetcode刷题系列]Merge Two Sorted Lists

最新推荐文章于 2022-10-05 16:58:24 发布

原创最新推荐文章于 2022-10-05 16:58:24 发布 · 495 阅读

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模拟题，又练习了指针的操作，感觉最近练习了不少了：）

/**
 * 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) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if(l1 == 0)
            return l2;
        if(l2 == 0)
            return l1;
        ListNode * ret, *cur;
        if(l1->val < l2->val){
            ret = l1;
            cur = l1;
            l1 = l1->next;
        }else{
            ret = l2;
            cur = l2;
            l2 = l2->next;
        }
        while(l1 != 0 || l2 != 0){
            if(l1 == 0){
                cur->next = l2;
                return ret;
            }
            if(l2 == 0){
                cur->next = l1;
                return ret;
            }
            if(l1->val < l2->val){
                cur->next = l1;
                cur = l1;
                l1 = l1->next;
            }else{
                cur->next = l2;
                cur = l2;
                l2 = l2->next;
            }
        }
        return ret;
    }
};