目录
思路分析
这个其实就是归并排序的归并步骤,只不过是链表的版本
cpp
/**
* 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) {
auto dummy = new ListNode(-1);
auto cur = dummy;
while(l1 && l2){
if(l1->val < l2->val){
cur->next = l1;
cur = cur->next;
l1 = l1->next;
}else{
cur->next = l2;
cur = cur->next;
l2 = l2->next;
}
}
while(l1){
cur->next = l1;
cur = cur->next;
l1 = l1->next;
}
while(l2){
cur->next = l2;
cur = cur->next;
l2 = l2->next;
}
return dummy->next;
}
};
python
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution:
def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
dummy = ListNode(-1)
cur = dummy
while l1 and l2:
if l1.val < l2.val:
cur.next = l1
cur = cur.next
l1 = l1.next
else:
cur.next = l2
cur = cur.next
l2 = l2.next
while l1:
cur.next = l1
cur = cur.next
l1 = l1.next
while l2:
cur.next = l2
cur = cur.next
l2 = l2.next
return dummy.next