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;
double sum,sum1=0;
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
if(i%2==0)
{
sum=-2*i/2.0;
}
else
{
sum=-2*(i-1)/2.0+(2*i-1);
}
sum1+=1.0/sum;
}
printf("%.3lf",sum1);
}
