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