谁能帮忙检查一下这题

#include <bits/stdc++.h>
using namespace std;

int main(){
    double x, gpa;
    cin >> x;
    if(x == 100){ cout << "Perfect" << endl;}
    if(x < 60){ cout << "0.000" << endl;}
    if(x >= 60){
        gpa = 4 - (3 * ((100 - x) * (100 - x))) / 1600;
        cout << fixed << setprecision(3) << gpa << endl;
    }
    return 0;
}

网址是: GPA计算 次次评测90分,求助大佬 烦劳发个c++的，谢谢?