编写程序用下面公式求π的近似值 π/4 ≈ 1- 1/3+1/5-1/7+…… 直到最后一项的绝对值小于10-7 为止

#includeusing namespace std;int main(){ int i = 1, sign = 1; double t = 1, pi = 0; while (fabs(t) >= 1e-7) { pi = pi + t; i = i + 2; sign = -sign; t = sign*1.0 / i; } cout << "pi= " << 4 * pi << endl; return 0;}