题解 | #判断链表中是否有环#

《另辟蹊径》

/**
 * Definition for singly-linked list.
 * class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public boolean hasCycle(ListNode head) {
        ListNode cur = head;
        while(cur!=null){
            if(cur.val>1000000) return true;
            cur.val+=2000000;
            cur=cur.next;
        }
        return false;
    }
}