+1 vote
in Data Structures & Algorithms I by (111k points)
Consider a small circular linked list. How to detect the presence of cycles in this list effectively?

(a) Keep one node as head and traverse another temp node till the end to check if its ‘next points to head

(b) Have fast and slow pointers with the fast pointer advancing two nodes at a time and slow pointer advancing by one node at a time

(c) Cannot determine, you have to pre-define if the list contains cycles

(d) Circular linked list itself represents a cycle. So no new cycles cannot be generated

This question is from Circular Linked List in section Abstract Data Types of Data Structures & Algorithms I

I had been asked this question during an online exam.

1 Answer

+1 vote
by (679k points)
selected by
Best answer
Correct choice is (b) Have fast and slow pointers with the fast pointer advancing two nodes at a time and slow pointer advancing by one node at a time

Best explanation: Advance the pointers in such a way that the fast pointer advances two nodes at a time and slow pointer advances one node at a time and check to see if at any given instant of time if the fast pointer points to slow pointer or if the fast pointer’s ‘next’ points to the slow pointer. This is applicable for smaller lists.

Related questions

Welcome to TalkJarvis QnA, a question-answer community website for the people by the people. On TalkJarvis QnA you can ask your doubts, curiosity, questions and whatever going in your mind either related to studies or others. Experts and people from different fields will answer.

Most popular tags

biology – class 12 biology – class 11 construction & building materials chemistry – class 12 electronic devices & circuits network theory data structures & algorithms ii cell biology ic engine insurance finance money computational fluid dynamics engineering physics i discrete mathematics chemistry – class 11 aerodynamics casting-forming-welding i engineering mathematics operating system casting-forming-welding ii engineering drawing mysql engineering geology digital circuits wireless mobile energy management electrical measurements digital communications cyber security analytical instrumentation embedded systems electric drives cytogenetics computer fundamentals life sciences basic civil engineering advanced machining iot design of electrical machines physics – class 12 applied chemistry dairy engineering basic chemical engineering cloud computing microprocessor bioinformatics aircraft design aircraft maintenance software engineering drug biotechnology digital signal processing biochemistry data structures & algorithms i automotive engine design avionics engineering material & metallurgy energy engineering cognitive radio unix electrical machines biomedical instrumentation object oriented programming electromagnetic theory power electronics analog communications bioprocess engineering civil engineering drawing engineering metrology physics – class 11 mathematics – class 12 engineering chemistry i basic electrical engineering unit processes mongodb signals and systems cryptograph & network security hadoop mathematics – class 11 engineering physics ii html control systems engineering mechanics antennas analog circuits computer network java sql server javascript concrete technology chemical process calculation artificial intelligence design of steel structures c++ database management computer architecture engineering chemistry ii corrosion engineering chemical technology dc machines