Detect Loop Start in Linked List | Dataford Interview Questions

Detect loop in linked-list if exist print the node data from where the loop starts

Asked in the Hackathon stage. Represent the linked list with parallel arrays: values[i] stores node data, and next_indices[i] stores the next node index or -1; head is the starting index. Return the data value at the first node in the loop, or None when no loop exists.

Constraints

0 <= len(values) <= 500
len(values) == len(next_indices)
0 <= head < len(values), or head == -1 when the list is empty
Each next index is -1 or an index from 0 through len(values) - 1

Function Signature

def find_loop_start(values, next_indices, head):

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Problem

Detect loop in linked-list if exist print the node data from where the loop starts

Constraints

0 <= len(values) <= 500
len(values) == len(next_indices)
0 <= head < len(values), or head == -1 when the list is empty
Each next index is -1 or an index from 0 through len(values) - 1

Function Signature

def find_loop_start(values, next_indices, head):

Your question is Detect Loop Start in Linked 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.