题解 | #判断链表中是否有环#

/**
 * 
 * @param head ListNode类 
 * @return bool布尔型
*/

// 快慢指针解决
func hasCycle( head *ListNode ) bool {
    // write code here
    fast := head
    slow := head 
    
    for fast != nil && fast.Next != nil {
        fast = fast.Next.Next
        slow = slow.Next
        if fast == slow {
            return true 
        }
    }
    
    return false 
}