376. Find Length of Loop in Linked List

Given a linked list, return the number of nodes in its loop, or 0 if there is no loop. The list is given as an array of values plus pos, the 0-based index that the tail connects to (pos = -1 means no loop). Input: '[list], pos'.

Input: '[list], pos'.

Output: Integer — loop length, or 0.

Examples

Input: [1,2,3,4,5], 1
Output: 4
Explanation: Loop covers indices 1..4.

Input: [1,2,3,4], 0
Output: 4
Explanation: Whole list loops.

Input: [1], -1
Output: 0
Explanation: No loop.

Constraints

• 0<=n<=10^4
• -1<=pos<n

Asked by