/// Leibniz series to approximate pi
/// ```
/// use algori::math::leibniz_pi;
/// let a: f64 = leibniz_pi(100000);
/// ```
pubfnleibniz_pi(count:usize)->f64{letmut pi =0.0;letmut n =1.0;letmut sign =1;for_in0..count {
pi +=1.0/ n * sign asf64;
sign =-sign;
n +=2.0;// println!(" pi is {}, n is {}",pi,n);
}return pi *4.0;}