Middle of the Linked List : Given a non-empty, singly linked list with head node head, return a middle node of linked list. If there are two middle nodes, return the second middle node. https://leetcode.com/explore/challenge/card/30-day-leetcoding-challenge/529/week-2/3290/

LinkedListMiddleNode.java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class LinkedListMiddleNode {

    public ListNode solve(ListNode head) {
        
        int size = 0;
        
        // Go to the last node to find the size
        ListNode current = head;
        while(current != null) {
            current = current.next;
            size++;
        }
        
        int middle = size/2;
        
        // Go to the middle node
        current = head;
        for(int i=0; i < middle; i++) {
            current = current.next;
        }
        
        return current;
    }
}