题解 | #牛牛学数列#
牛牛学数列
https://www.nowcoder.com/practice/0b97367cd2184c12a0e02f7c223aee11
#include <stdio.h>
int main()
{ int a;
int sum=0;
scanf("%d",&a);
for(int i=0;i<=a;i++){
if (i%2!=0) {
sum+=i;
}
else{
sum-=i;
}
}
printf("%d",sum);
}