tpx045 • 9个月前
using namespace std; int main() {
long long a,n,an,s=0; cin>>a; if(a%10<5) { n=a/10-1; } else n=a/10; if((a-10)%5>=1) { an=(a-10)/5; } else an=(a-10)/5-1; for(int i=an;i>=0;i-=2) { s=s+i; } cout<<s; return 0;
}
评论: