// dsaI_17_31.java SJ

import fi.joensuu.cs.tra.Set;
import java.util.Random;
import java.util.TreeSet;
import java.util.HashSet;

public class dsaI_17_31_skeleton {

	public static void main(String[] args) {

		int N = 10;
		if (args.length > 0)
			N = Integer.valueOf(args[0]);


		Set<Integer> S1 = new Set<Integer>();
		Set<Integer> S2 = new Set<Integer>();
		Set<Integer> S3 = new Set<Integer>();

		Random r = new Random(42);
		Integer x, y;
		for (int i = 0; i < N; i++) {
			x = r.nextInt(N*2);
			S1.add(x);
			y = r.nextInt(N*2);
			S2.add(x-y);
			S3.add(x+y);
		}


		System.out.println("S1:      " + S1);
		System.out.println("S2:      " + S2);
		System.out.println("S3:      " + S3);


		System.out.println("twoOutFromThreeTRA: " + twoOutFromThree(S1, S2, S3));

        TreeSet<Integer> TS1 = new TreeSet<Integer>(S1);
        TreeSet<Integer> TS2 = new TreeSet<Integer>(S2);
        TreeSet<Integer> TS3 = new TreeSet<Integer>(S3);

        System.out.println("twoOutFromThreeJava: " + twoOutFromThree(TS1, TS2, TS3));


	} // main()


    /**
      * 31. Write an algorithm that creates a ”two out of three” intersection
      * of sets. Algorithm gets as pa- rameter three sets, and creates a new
      * set that contains those elements that are contained in ex- actly two
      * input sets (not all three, not less than two). You can use either
      * JavaAPI sets, or TRA- library set. Do not change the input sets. What
      * is the time complexity of your algorithm?
      **/

    // TRA version
	public static <E> Set<E> twoOutFromThree(Set<E> A, Set<E> B, Set<E> C) {

        // TODO

        return null;

	} // twoOutFromThree()
		
    // JavaAPI version
	public static <E> TreeSet<E> twoOutFromThree(TreeSet<E> A, TreeSet<E> B, TreeSet<E> C) {

        // TODO

        return null;
	} // twoOutFromThree()
		


} // class dsaI_17_31