Mistake : Forgetting that cycles exist. If you simulate without a visited set, you loop forever. Always track visited nodes or use Floyd's algorithm to detect cycles early. Infinite loops are common bugs. Mistake : Off-by-one errors in cycle indices. Cycle positions are modular, and fencepost errors are common.
Test with small examples to catch these bugs. The modulo operation is tricky. Mistake : Not handling the tail separately. Algorithms that assume all nodes are in cycles fail on tail nodes. Separate tail and cycle logic explicitly. Each region needs different handling. This separation is critical.