Middle of the Linked List
Problem Statement - link #
Given the head of a singly linked list, return the middle node of the linked list.
If there are two middle nodes, return the second middle node.
Examples #
Example 1:
Input: head = [1,2,3,4,5]
Output: [3,4,5]
Explanation: The middle node of the list is node 3.
Example 2:
Input: head = [1,2,3,4,5,6]
Output: [4,5,6]
Explanation: Since the list has two middle nodes with values 3 and 4, we return the second one.
Constraints #
The number of nodes in the list is in the range [1, 100]1 <= Node.val <= 100
Solutions #
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
class Solution {
public:
ListNode* middleNode(ListNode* head) {
ListNode* mid = head;
ListNode* last = head;
while( last != NULL && last->next != NULL){
mid = mid -> next ;
last = last -> next -> next ;
}
return mid;
}
};