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

/*
 * Lab 4
 *
 * Author: Robin Dawes
 *
 * Date: 20081022
 *
 * Comment: 
 *
 */

public class ChipTest {
    
    static int instances;
    static int numOfChips;
    static Chip[] setOfChips;
    
    
    public static void main (String[] argv) throws Exception {
        Scanner myScanner = new Scanner(new File("Lab_4_Data.txt"));
        // find out how many instances
        instances = myScanner.nextInt();
        for (int i = 0; i < instances; i++) {
            // read in the data for the next instance
            numOfChips = myScanner.nextInt();
            setOfChips = new Chip[numOfChips];
            System.out.println("\nInstance " + i);
            //System.out.print("Input : ");
            for (int j = 0; j < numOfChips; j++){
                int nextChip = myScanner.nextInt();
                //System.out.print(nextChip + "  ");
                setOfChips[j] = new Chip(j, nextChip);
            }
            //System.out.println();
            // find a good chip
            int indexOfGoodChip = recursiveTest(numOfChips, setOfChips);
            System.out.println("One good chip : " + indexOfGoodChip);
            // list the good chips
            System.out.print("The good chips are ");
            for (int j = 0; j < numOfChips; j++)
                if (setOfChips[indexOfGoodChip].checkChip(setOfChips[j]))
                    System.out.print(j + "   "); 
            System.out.println();                    
        }
    } // main
    
    static int recursiveTest(int n, Chip[] s) {
        /*
        System.out.print("Chips still in consideration : ");
        for (int i = 0; i < n; i++)
            System.out.print(s[i].getIndex() + "  ");
        System.out.println();
        */
        if (n == 1) return s[0].getIndex();
        else if (n == 3) {
                if (s[0].checkChip(s[1]) && s[1].checkChip(s[0])) return s[0].getIndex();
                else return s[2].getIndex();
        }
        else {
            Chip[] reducedSet = new Chip[n/2 + 1];
            int reducedSetSize = 0;
            int numCheckable = n - (n%2);  // if n is odd, we can't check the last chip
            // keep one out of each pair that reports both chips are good
            for (int i = 0; i < numCheckable; i+=2){
                if (s[i].checkChip(s[i+1]) && s[i+1].checkChip(s[i])) {
                    reducedSet[reducedSetSize] = s[i];
                    reducedSetSize++;
                }
            }
            // If the original set was odd in size, the last chip has not been
            // tested against any other.  If the reduced set is even in size, we
            // add the last chip to it - if the reduced set is odd in size, we
            // don't need the last chip so we leave it out.
            if ((n%2 == 1) && (reducedSetSize%2 == 0)) {
                reducedSet[reducedSetSize] = s[n-1];
                reducedSetSize++;
            }
            return recursiveTest(reducedSetSize, reducedSet);
        }
    } // recursiveTest

} // class