ConnectJoinAlgorithm.java

import java.util.Arrays;

public class ConnectJoinAlgorithm {

    static int[] id;
    static int[] integers;

    static int N = 10;

    public static void main(String[] args) {
        id = new int[N];
        integers = new int[N];

        for (int i = 0; i < N; i++) {
            id[i] = i;
        }
        // Copy the id array to a new integers array; intergers[] stores the values we are connecting and tracking
        System.arraycopy(id, 0, integers, 0, N);
        // Print initial id array before any connections are made
        System.out.println(Arrays.toString(id));


        System.out.println(find(4, 9)); // 4 and 9 have not been connected; this should evaulate to false
        connect(4, 3);
        System.out.println(Arrays.toString(id));

        connect(8, 3);
        System.out.println(Arrays.toString(id));

        System.out.println(find(3, 8)); // Since we connected 3 and 8 this should evaluate to true
        System.out.println(find(4, 8)); // Since we connected 4 and 8 via 3 this should evaluate to true

    }

    public static boolean find (int p, int q) {
        return (id[p] == id[q]);
    }

    public static void connect(int p, int q) {
        int idp = id[p];
        int idq = id[q];

        for (int i = 0; i < N; i++) {
            if (id[i] == idp) {
                id[i]  = idq;
            }
        }
    }


}