Find Length of a Cycle in Linked List
Given a linked list with a cycle, determine the number of nodes in the cycle.
Input format
The first line contains N and POS — the 0-based index the last node links back to (a cycle always exists). The second line contains the N node values.
Output format
Print the number of nodes in the cycle.
Constraints
- Values fit in a 64-bit signed integer
- Trailing whitespace and a trailing newline are ignored by the judge
Read from stdin, write to stdout. Sample cases below show the exact format.
Sample cases
Example 1
Input
5 1
1 2 3 4 5Expected output
4Example 2
Input
1 0
7Expected output
1