题解 | #牛牛学数列3#
牛牛学数列3
https://www.nowcoder.com/practice/f65c726d081c4160a9356eabf0dc21d9
#include <stdio.h>
int main() {
int n, i;
double sum=0;
scanf("%d",&n);
for(i=1;i<=n;i++)
{
if(i%2==0)
{
i=i*(-1);
sum+=1.0/(double)i;
i=i*(-1);
}else
{
sum+=1.0/(double)i;
}
}
printf("%.3f",sum);
return 0;
}
