LeetCode in Kotlin
876. Middle of the Linked List
Easy
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.
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
Solution
import com_github_leetcode.ListNode
/*
* Example:
* var li = ListNode(5)
* var v = li.`val`
* Definition for singly-linked list.
* class ListNode(var `val`: Int) {
* var next: ListNode? = null
* }
*/
class Solution {
fun middleNode(head: ListNode?): ListNode? {
var fast = head
var slow = head
while (fast?.next != null) {
fast = fast.next!!.next
slow = slow!!.next
}
return slow
}
}