题解 | #求 1 - n 之间偶数的和#

#include <iostream>
using namespace std;
#define two = 2;
int main() {
    int n = 0;
    int m = 1;
    int total = 0;
    scanf("%d",&n);
    while(m<=n){
        if(m%2==0){
            total = total + m;
            m++;
        }
        else{
            m++;
        }
    }
    printf("%d",total);
    return 0;
}