Question

看看这题c++算π怎么算？4(1 - 1/3 + 1/5 - 1/7 + 1/9 - ... -1/(2n-1) + 1/(2n+1))

m(i) = 4(1 - 1/3 + 1/5 - 1/7 + 1/9 - ... -1/(2n-1) + 1/(2n+1))
Write a function that returns m(n) with the following function head.

double pi(int n)

提示
You should submit the implementation of the function but do not submit the main() function.

Answer 1

#include<stdio.h>
#include<math.h>
double pi(int n)
{
double sum = 1;
for(int i = 1;i <= n;i ++)
{
sum += 1.0/(2*n + 1) * (pow(-1,n));

}
return sum * 4;
}
int main()
{
printf("%f\n",pi(1));

return 0;
}