Dominos arrangement (Java Coding)

Question

I am trying to use Java to solve the following.

Given an arrangement of dominos, determine, whether or not it is a legal arrangement and return True or False accordingly. For example, this is an illegal arrangement [2 3][4 2][2 2][3 5] and this is a legal arrangement of Dominos. [2 3][3 5][5 4][4 5].

I have no clue how to begin this to write this program.

Answer 1

Write a Domino class

public class Domino {
    private int leftValue;
    private int rightValue;

    public Domino(int leftValue, int rightValue) {
        this.leftValue = leftValue;
        this.rightValue = rightValue;
    }

    public int getLeftValue() {
        return leftValue;
    }

    public int getRightValue() {
        return rightValue;
    }
}

Create an array or list containing the domino's

Domino[] dominos = new Domino[] {
            new Domino(2, 3),
            new Domino(3, 2),
            new Domino(2, 5),
            new Domino(2, 5)
        };

Loop and match left and right values

    Domino previous = null;
    for (Domino current : dominos) {
       if (previous != null) {
          if (current.getLeftValue() != previous.getRightValue()) {
             throw new Exception("Illegal arrangement detected");
          }
       }
       previous = current;
    }