#include <opencv2/opencv.hpp>

#include <iostream>

using namespace std;

using namespace cv;

int main()

{

	const int side=100;

	const int npixels=8000;

	int i,j;

	Mat s1=Mat::zeros(side, side, CV_8UC1); // 背景黑色

	Mat s2=s1.clone();

	circle(s1, Point(side/2, side/2), side/2, 255, -1); // 白色填充的圆

	imshow("s1", s1);

	for (int k=0; k<npixels;k++)

	{

		i = rand()%side;

		j = rand()%side;

		s2.at<uchar>(i, j)=255;

	}

	Mat r;

	bitwise_and(s1, s2, r);

	imshow("s2", s2);

	imshow("r", r);

	int Acircle = countNonZero(r);

	int Asquare = countNonZero(s2);

	float Pi=4*(float)Acircle/Asquare;

	cout << "Estimated value of Pi:"<<Pi<<endl;

	waitKey();

	return 0;

}