剑指offer之合并两个排序的链表

题目描述

输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。

示例1

输入

{1,3,5},{2,4,6}

返回值

{1,2,3,4,5,6}

/*
struct ListNode {
	int val;
	struct ListNode *next;
	ListNode(int x) :
			val(x), next(NULL) {
	}
};*/
class Solution {
public:
    ListNode* Merge(ListNode* pHead1, ListNode* pHead2)
    {
        if(pHead1==NULL) return pHead2;
        if(pHead2==NULL) return pHead1;
        ListNode* rt = NULL;
        ListNode* cur = NULL;
        ListNode* pre = NULL;
        if(pHead1->val < pHead2->val)
        {
            rt = pHead1;
        }
        else
        {
            rt = pHead2;
        }
        while(pHead1 != NULL && pHead2 != NULL)
        {
            if(pHead1->val < pHead2->val)
            {
                cur = pHead1;
                pHead1 = pHead1->next;
            }
            else
            {
                cur = pHead2;
                pHead2 = pHead2->next;
            }
            if(pre != NULL)
            {
                pre->next = cur;
            }
            pre = cur;
        }
        if(pHead1 == NULL)
        {
            cur->next = pHead2;
        }
        if(pHead2 == NULL)
        {
            cur->next = pHead1;
        }
        return rt;
    }
};

标签：NULL,ListNode,cur,offer,next,链表,pHead1,pHead2,排序
来源： https://blog.csdn.net/A18373279153/article/details/113814595