用C语言或者C++编程

Question

编程计算s=1-1/2+1/3-1/4+1/5-1/6+…+1/n

Answer 1

#include<stdio.h>
#include<math.h>
int main(void)
{
int a,n;
double sum=0;
scanf("%d",&n);
for(a=1;a<=n;a++)
{
sum = sum+pow(-1,a+1)*(1.0/a);
}
printf("%f\n",sum);
return 0;

}