Linkedlists : Linked List Cycle

hasCycle.go

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func hasCycle(head *ListNode) bool {
    
    dummy := head 
    arr := []*ListNode{}
    for dummy != nil {
        for _, n := range arr {
            if dummy.Next == n {
                return true
            } 
        }
        arr = append(arr, dummy)
        dummy = dummy.Next
    }
    
    return false
}