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 x=1.0f; float sum=1.0f; float y=1.0f; for(i=1;i<n;i++) { x+=2; if(i%2!=0) sum-=x; else sum+=x; y=y+1/sum; } printf("%.3f",y); return 0; }