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() { double a=1.0,result=0.0,input=0.0,b=1.0; scanf("%lf",&input); for(int i=1;i<input+1;i++) { b=a; if(i%2==0) b=-b; else b=b; a++; result+=1/b; } printf("%.3lf",result); return 0; }