09. Points inside the House

import java.util.Scanner;

public class _09_PointsInsideTheHouse {
    private static final double X1 = 12.5;
    private static final double X2 = 8.5;
    private static final double X3 = 22.5;
    private static final double X4 = 20;
    private static final double Y1 = 8.5;
    private static final double Y2 = 17.5;
    private static final double Y3 = 3.5;
    private static final double Y4 = 13.5;

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double x = scanner.nextDouble();
        double y = scanner.nextDouble();

        boolean isInsideFirstFigure = (
                x >= X1 && x <= Y2)
                && (y >= X2 && y <= Y4);

        boolean isInsideSecondFigure = (
                x >= X4 && x <= X3)
                && (y >= Y1 && y <= Y4);

        boolean isInsideThirdFigure = isInsideTriangle(x, y, X1, X2, X3, Y1, Y2, Y3);

        if (isInsideFirstFigure || isInsideSecondFigure || isInsideThirdFigure) {
            System.out.println("Inside");
        }
    else {
            System.out.println("Outside");
        }
    }

    private static boolean isInsideTriangle(double x, double y, double x1, double y1, double x2, double y2, double x3, double y3) {
        double ABC = Math.abs(x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2));
        double ABP = Math.abs(x1 * (y2 - y) + x2 * (y - y1) + x * (y1 - y2));
        double APC = Math.abs(x1 * (y - y3) + x * (y3 - y1) + x3 * (y1 - y));
        double PBC = Math.abs(x * (y2 - y3) + x2 * (y3 - y) + x3 * (y - y2));

        boolean isInTriangle = ABP + APC + PBC == ABC;
        return isInTriangle;
    }
}