编辑代码

#include <stdio.h>
int main(void)
{
    double term,result = 1;
    for(int n=2;n<=100;n=n+2)
    {
        term = (double)(n*n)/((n-1)*(n+1));
        result = result * term;
    }
    printf("result = %f\n",2*result);
    return 0;
}