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