You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

14 lines
354 B

#include <bits/stdc++.h>
using namespace std;
int main() {
//cin读入优化
std::ios::sync_with_stdio(false);
float n;
cin >> n;
if (n >= 0 && n < 5) printf("%.3f", 0 - n + 2.5);
else if (n >= 5 && n < 10) printf("%.3f", 2 - 1.5 * (n - 3) * (n - 3));
else if (n >= 10 && n < 20) printf("%.3f", n / 2 - 1.5);
return 0;
}