C++求圓周率

用下面的公式求Π的近似值

Π 4 \frac{Π}{4} 4Π​=1- 1 3 \frac{1}{3} 31​+ 1 5 \frac{1}{5} 51​- 1 7 \frac{1}{7} 71​+……

直到最後一項的絕對值小于 1 0 − 7 10^{-7} 10−7

#include<iostream>
#include<iomanip>
#include<cmath>
using namespace std;
int main()
{
	int s = 1;
	double n = 1, t = 1, pi = 0;
	while (fabs(t)>1e-7)
	{
		pi = pi + t;
		n += 2;
		s = -s;
		t = s / n;
	}
	pi = pi * 4;
	cout << "Π=" << setiosflags(ios::fixed) << setprecision(6) << pi << endl;
	system("pause");
	return 0;
}
           

運作結果