import java.util.*;
import java.io.*;

class TSPEvaluator extends Evaluator {
    
    private ArrayList<Integer> X,Y;
    private float[][] Cost;
    private int n;

    public TSPEvaluator(String fname) throws IOException {
	X           = new ArrayList<Integer>();
	Y           = new ArrayList<Integer>();
	Scanner sc  = new Scanner(new File(fname));
	while (sc.hasNext()){
            X.add(sc.nextInt());
            Y.add(sc.nextInt());
        }
	sc.close();
	makeCostMatrix();
    }

    private void makeCostMatrix(){
	n    = X.size();
	Cost = new float [n][n];
	float x,y;
	for (int i=0;i<n-1;i++)
	    for (int j=i+1;j<n;j++){
		x = (float)(X.get(i) - X.get(j)); 
		y = (float)(Y.get(i) - Y.get(j));
		Cost[i][j] = Cost[j][i] = (float)Math.sqrt(x*x + y*y);
	    }
    }

    public float evaluate(int[] permutation){
	float cost = (float)0.0;
	for (int i=0;i<n-1;i++) cost = cost + Cost[permutation[i]][permutation[i+1]];
	cost = cost + Cost[permutation[0]][permutation[n-1]];
	return ((float)1.0)/cost;
    }

    public int getSize(){return n;}

}