#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin >> n;
	cout << fixed << setprecision(2) << n / 4.0 * n / 4.0 << endl;
    return 0;
}

//已AC，请放心食用❤️ (能给个赞吗？)

#include <bits/stdc++.h>
using namespace std;
int main(){
    int n;
    double b , r;
    cin >> n;
    b = n / 4;
    r = b * b;
    cout << fixed << setprecision(2) << r << endl;
    return 0;
}
```给我点赞的都是大佬👍 

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int c;//定义变量周长
    double a;//定义变量边长
    cin>>c;//输入周长
    a=c/4.0;//算出边长
    cout<<fixed<<setprecision(2)<<a*a;//算出面积并保留两位小数再打印
    return 0;

}

#include <bits/stdc++.h>
using namespace std;
int main()
{
    float a;
    cin>>a;
    a=a/4;
    a=a*a;
    printf("%.2f",a);
    return 0;
}

6

#include<bits/stdc++.h>
using namespace std;
int main()
{
    double m,s;
    cin>>m;
    s=(m/4)*(m/4);
    cout<<fixed<<setprecision(2)<<s;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    double a , b;
    cin >> a;
    a = a / 4;
    b = a * a;
    printf("%.2f",b);
    return 0;
}

A