使用Java Math.random()利用蒙特卡洛方法计算pi值

/**
* Monte Carlo algorithm
*/
import java.math.*;

public class PI {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
double xf = 0.0d;
double yf = 0.0d;
int total = 0;
for(int i = 0;i<1000000;i++){
xf = Math.random();
yf = Math.random();
if(Math.sqrt(xf*xf+yf*yf) < 1)
total++;
}

System.out.println(4*(total/1000000.0));
}

}