Loop Solution - Linked List Cycle II - Math

There is a formula for his question: t mod n = (k + 2t) mod n


/**
 * Definition for singly-linked list.
 * class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode detectCycle(ListNode head) {
        if(head == null || head.next == null){
            return null;
        }
        ListNode oneStep = head;
        ListNode twoStep = head;
       
        while(twoStep != null && twoStep.next != null ){
            oneStep = oneStep.next;
            twoStep = twoStep.next.next;
            if(oneStep == twoStep){
                break;
            }
        }
        if(twoStep == null || twoStep.next == null){
            return null;
        }else{
            oneStep = head;
            while(oneStep != twoStep){
                oneStep = oneStep.next;
                twoStep = twoStep.next;
            }
        }
        return oneStep;
    }
}