package main import . "nc_tools" /* * type ListNode struct{ * Val int * Next *ListNode * } */ /** * * @param head ListNode类 * @return bool布尔型 */ func hasCycle( head *ListNode ) bool { if head==nil || head.Next==nil{ return false } fast,slow := head,head for true { slow = slow.Next fast = fast.Next.Next if fast == nil ||fast.Next == nil { return false } if slow.Val == fast.Val{ return true } } return false }