rt，第6个和第7个点错了,怎么办？

#include<bits/stdc++.h>
using namespace std;
int main()
{
	long long x;
	cin>>x;
	if(x>=90) cout<<"4.0"<<endl;
	else if(x>=60) cout<<fixed<<setprecision(1)<<4.0-(90-x)*0.1<<endl;
	else 
	{
	    if(floor(sqrt(x)*10<60)) cout<<"0.0"<<endl;
	    else cout<<fixed<<setprecision(1)<<4.0-(90-x)*0.1<<endl;
	}
    return 0;
}