Detecting a Cycle in a List | Dataford Interview Questions

Write a function to check for the presence of a cycle in a linked list.

Represent the linked list with nodes, where each node is an object containing value and next. The next field is the zero-based index of the next node, or -1 for the end of the list. head is the starting index. Return True if traversal can revisit a node, otherwise return False.

Constraints

0 <= len(nodes) <= 10^4
Each node contains a value and a next index
Each next index is -1 or a valid index in nodes
head is -1 for an empty list or a valid node index

Function Signature

def has_cycle(nodes, head):

Your question is Detecting a Cycle in a List. Start with the requirements in the Question tab.

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Problem

Write a function to check for the presence of a cycle in a linked list.

Constraints

0 <= len(nodes) <= 10^4
Each node contains a value and a next index
Each next index is -1 or a valid index in nodes
head is -1 for an empty list or a valid node index

Function Signature

def has_cycle(nodes, head):

Your question is Detecting a Cycle in a List. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.