【LeetCode】21. Merge Two Sorted Lists

LeetCode-21

Links:https://leetcode.com/problems/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.

思路：链表合并…Merge函数…

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

/**

* 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* temp = new ListNode(0);

ListNode* tempptr = temp;

if(l2==NULL)return l1;

if(l1==NULL)return l2;

while(l1!=NULL && l2!=NULL)

{

if(l1->val < l2->val)

{

tempptr->next = l1;

l1 = l1->next;

}

else{

tempptr->next = l2;

l2 = l2->next;

}

tempptr->next->next = NULL;

tempptr = tempptr->next;

}

if(l1!=NULL)

{

tempptr->next = l1;

}

if(l2!=NULL)

{

tempptr->next = l2;

}

return temp->next;

}

};

【LeetCode】21. Merge Two Sorted Lists

Tagged on: LeetCode