import lombok.*;

/** Définir une position.  */
@Data @Value
public class Position {
	public int x;
	public int y;

	// public Position(int x, int y) {
	// 	this.x = x;
	// 	this.y = y;
	// 	// <(NO_TRACE)>// <(/NO_TRACE)>System.out.println("...appel à Position(" + x + "," + y + ")" + " --> " + this);
	// 	System.out.println("...appel à Position(" + x + "," + y + ")" + " --> " + this);
	// }

	@Override
	public String toString() {
		return super.toString() + "(" + x + "," + y + ")";
	}

	@Override
	public boolean equals(Object obj) {
		Position other = (Position) obj;
		return other.x == this.x && other.y == this.y;
	}

	@Override
	public int hashCode() {
		// bijection de Z dans N
		int n, m;
		if (this.x >= 0) {
			n = 2 * this.x;
		} else {
			n = -2 * this.x - 1;
		}
		if (this.y >= 0) {
			m = 2 * this.y;
		} else {
			m = -2 * this.y - 1;
		}

		// bijection de N² dans N
		int h = (n+m)*(n+m+1)/2+m;
		return h;
	}

}