题解 | 牛牛学数列
牛牛学数列
https://www.nowcoder.com/practice/0b97367cd2184c12a0e02f7c223aee11
#include <iostream>
using namespace std;
int main() {
int n, sum = 0;
cin >> n;
for (int i = 1; i <= n; i++) {
if (i % 2 == 0) {
sum -= i;
} else {
sum += i;
}
}
cout << sum << endl;
}
// 64 位输出请用 printf("%lld")
