point_inside_triangle

package maricka.kolokolova;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		double x;
		double y;

		System.out.println("Input x:");
		x = sc.nextDouble();

		System.out.println("Input y:");
		y = sc.nextDouble();

		int xa = 0;
		int ya = 0;

		int xb = 4;
		int yb = 4;

		int xc = 6;
		int yc = 1;

		double s;
		double sbc;
		double sac;
		double sab;

		s = (xa - xc) * (yb - yc) - (xb - xc) * (ya - yc);
		sbc = (x - xc) * (yb - yc) - (xb - xc) * (y - yc);
		sac = (xa - xc) * (y - yc) - (x - xc) * (ya - yc);
		sab = (x - xb) * (ya - yb) - (xa - xb) * (y - yb);

		if ((s < 0 && s <= sbc && sbc <= 0 && s <= sac && sac <= 0 && s <= sab && sab <= 0)
				|| (s > 0 && s >= sbc && sbc >= 0 && s >= sac && sac >= 0 && s >= sab && sab >= 0)) {
			System.out.println("Your point is inside the triangle.");
		} else {
			System.out.println("Your point is outside the triangle.");
		}

		sc.close();

	}

}