package mathComputations;

import java.lang.Math; // needed for Random method

public class approxPi {
    // class provides a framework for checking whether the parentheses
    // in a line of input match

    public static void main (String args [])
        throws Exception {

        // Declarations
        int N = 1000;  // Number of points to be selected
        int count = 0; // Count of points in circle
        int i;         // loop index
        double x, y; // coordinates for a randomly-generated point

        // simulate the selection of N points
        for (i = 0; i < N; i = i + 1) {
            // pick a random x and y value
            x = Math.random(); // returns a number >=0 and < 1.0
            y = Math.random();
            // check if point is in circle of radius 1.0
            if (x*x + y*y <= 1.0)
                count = count + 1;
        }
        
        System.out.println ("In selecting " + N + " points in the unit square");
        System.out.println ("in the first quadrant, " + count + " points ");
        System.out.println ("were also in the unit circle.");
        System.out.println ("This gives " + 4.0*count/N 
                            + " as an approximation to Pi.");
    }
}