圆周率c++.txt

一个实验

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
int main()
{
	double a=-1,p=1,b=3;
	for (b=3;b<99999999;b=b+2)
	{
	p=p+1/b*a;
		a=-a;
	}
	p=p*4;
	cout<<"pi="<<p<<endl;
	
	cin>>p;
return 0;
}