98.根据公式求值

函数fun的功能是：求S的值。S=(2k)*（2k）/(2k-1)(2k+1).

#define _CRT_SECURE_NO_WARNINGS
#include
#include
double fun(int k)
{
	int n;
	double s, w, q, p;
	n = 1;
	s = 1.0;
	while (n <= k)
	{
		w = 2.0*n;
		p = w - 1.0;
		q = w + 1.0;
		s = s*w*w / p / q;
		n++;
	}
	return s;
}
int main()
{
	printf("%lf\n", fun(10));
	system("pause");
	return 0;
}