45 lines
2.0 KiB
Java
45 lines
2.0 KiB
Java
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/*This is a Java Program to check whether a point lies below, above or on the line. For any point t (xt, yt) on the plane, its position with respect to the line L connecting p and q is found by calculating the scalar s:
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s = A xt + B yt + C
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If s < 0, t lies in the clockwise halfplane of L; if s > 0, t lies on the counter-clockwise halfplane; if s = 0, t lies on L.
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For example, the equation of the line connecting points (2, 2) and (4, 5) is -3x + 2y + 2 = 0. The point (6, 3) lies in the clockwise halfplane of this line, because (-3)(6) + (2)(3) + 2 = -10. Conversely, the point (0, 5) lies in the other halfplane as (-3)(0) +(2)(5) +2 = 12.*/
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//This is a java program to check whether a point lies on, above or below the gievn line
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import java.util.Random;
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import java.util.Scanner;
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public class Position_Point_WRT_Line
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{
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public static void main(String args[])
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{
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Random random = new Random();
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int x1, x2, y1, y2;
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x1 = random.nextInt(10);
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x2 = random.nextInt(10);
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y1 = random.nextInt(10);
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y2 = random.nextInt(10);
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System.out.println("The Equation of the line is : (" + (y2 - y1)
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+ ")x+(" + (x1 - x2) + ")y+(" + (x2 * y1 - x1 * y2) + ") = 0");
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System.out.println("Enter the point : <x>,<y>");
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Scanner scan = new Scanner(System.in);
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int x, y;
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x = scan.nextInt();
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y = scan.nextInt();
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int s = (y2 - y1) * x + (x1 - x2) * y + (x2 * y1 - x1 * y2);
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if (s < 0)
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System.out
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.println("The point lies below the line or left side of the line");
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else if (s > 0)
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System.out
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.println("The point lies above the line or right side of the line");
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else
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System.out.println("The point lies on the line");
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scan.close();
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}
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}
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/*
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The Equation of the line is : (-2)x+(-9)y+(81) = 0
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Enter the point : <x>,<y>
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2
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3
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The point lies above the line or right side of the line
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