24 lines
369 B
Ruby
24 lines
369 B
Ruby
|
def find_linked_list_cycle(list)
|
||
|
|
return false unless list
|
||
|
|
slow = list.head
|
||
|
|
fast = list.head
|
||
|
|
|
||
|
|
while fast && !fast.next.nil?
|
||
|
|
slow = slow.next
|
||
|
|
fast = fast.next.next
|
||
|
|
if slow == fast
|
||
|
|
break
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
return false if fast.nil? || fast.next.nil?
|
||
|
|
|
||
|
|
until slow == fast
|
||
|
|
slow = head
|
||
|
|
slow = slow.next
|
||
|
|
fast = fast.next
|
||
|
|
end
|
||
|
|
|
||
|
|
fast
|
||
|
|
end
|