题解 | #牛牛学数列#
牛牛学数列
https://www.nowcoder.com/practice/0b97367cd2184c12a0e02f7c223aee11
#include <stdio.h>
int main() {
int flag = 1, i = 0, n = 0, sum = 0;
scanf("%d", &n);
for (i = 1; i <= n; i++) {
sum = sum + flag * i;
flag = -flag;
}
printf("%d", sum);
return 0;
}
