package leetcode

import (
	"github.com/halfrost/LeetCode-Go/structures"
)

// ListNode define
type ListNode = structures.ListNode

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */

func hasCycle(head *ListNode) bool {
	fast := head
	slow := head
	for fast != nil && fast.Next != nil {
		fast = fast.Next.Next
		slow = slow.Next
		if fast == slow {
			return true
		}
	}
	return false
}