How to use two numbers as a Map key

Question

I have two numbers and I want to use them together as a key in a Map. Currently, I\'m concatenating their string representations. For example, suppose the key n

Answer 1

You can store two integers in a long like this,

   long n = (l << 32) | (r & 0XFFFFFFFFL);

Or you can use following Pair class,

public class Pair {

    private L l;
    private R r;

    public Pair() {
    }

    public Pair(L l, R r) {
        this.l = l;
        this.r = r;
    }

    public L getLeft() {
        return l;
    }

    public R getRight() {
        return r;
    }

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof Pair)) {
            return false;
        }
        Pair obj = (Pair) o;
        return l.equals(obj.l) && r.equals(obj.r);
    }

    @Override
    public int hashCode() {
        return l.hashCode() ^ r.hashCode();
    }
}