题解 | 求 1 - n 之间偶数的和
求 1 - n 之间偶数的和
https://www.nowcoder.com/practice/03df7fa0950046a9ba564b4438f918a3
#include <iostream>
using namespace std;
int main() {
int n;
cin >> n;
int sum = 0;
// write your code here......
sum=(n%2)?(n-1)/2*(n+1)/2:n/2*(n/2+1);
cout << sum << endl;
return 0;
}
