#include "iostream.h"
#include "math.h"
#include "stdlib.h"

void main()
{
	int count=0,total=8000;
	double x,y,z,pi,a,s;
	cout<<"輸入試驗次數: "<<'\n';
	cin>>total;
	for(int i=0;i<total;i++)
	{	
		a=(rand()*1.0)/RAND_MAX;
		do
		{
			x=(rand()*1.0)/RAND_MAX;
			y=(rand()*1.0)/RAND_MAX;
		}
		while(x*x+y*y>=1);
		s=x/sqrt(x*x+y*y);
		z=a+s;
		if(z>1||z<0)
			count++;
	
		if(i%1000==1)
		{
			pi=2.0*i/count;
			cout<<pi<<'\n';
		}
	}
}