Determine the closed loop of a single-linked list

Has the following data structure

Class node{public    int Value {get; set;}    Public Node Next {get; set;}}

　　

The existing Node node object, which represents a one-way list, determines whether this one-way list has a ring

public bool Iscricle (node node) {    node fast = node;    node slow = node;    while (node. Next! = null)    {        slow = slow. Next;        Fast = fast. Next;        if (fast! = null && fast. Next! = null)            fast = fast. Next;        else            return false;        node = node. Next;        if (fast = = slow)            return true;    }    return false;}

Using two pointers, the fast pointer walks two nodes at a time, the slow pointer walks one node at a time, and if there is a ring, the fast pointer is bound to point to the same node at some point with the slow pointer.

Determine the closed loop of a single-linked list