题解 | #求 1 - n 之间偶数的和#

#include <iostream>
using namespace std;

int main() {
    
    int n;
    cin >> n;
    int sum = 0;
    int i;
    if(n!=2)
    {
        for (i=2;i<=n;i+=2)
        {
            sum=i+sum;
        }// write your code here......
    }
    else if (n=2)
    {
        sum=2;
    }
    cout << sum << endl;//打印
    
    return 0;
}