codewars #84Can you get the loop ? (5kyu)

#84Can you get the loop ?

You are given a node that is the beginning of a linked list. This list always contains a tail and a loop.

Your objective is to determine the length of the loop.

For example in the following picture the tail's size is 3 and the loop size is 11.

// Use the `getNext()` method to get the following node.

node.getNext()

Note: do NOT mutate the nodes!

Thanks to shadchnev, I broke all of the methods from the Hash class.

Don't miss dmitry's article in the discussion after you pass the Kata !!

import java.util.ArrayList;
import java.util.List;
 
public class LoopInspector {
 
  public int loopSize(Node node) {
   
    List<node> list = new ArrayList<>();
    int index =0;
    while(true){
      index = list.indexOf(node);
      if(index == -1)
        list.add(node);
      else
        break;
      node = node.getNext();
    }
     
    return list.size()-index;
   
  }
 
}