#include<bits/stdc++.h>

using namespace std;

int main()
  
{
  
	double a,b,c,ans1,ans2;
  
	cin>>a>>b>>c;
  
	if ((b*b-4*a*c)>=0)
      
	{
      
		ans1=(-b+sqrt(b*b-4*a*c))/(2*a);
      
		ans2=(-b-sqrt(b*b-4*a*c))/(2*a);
      
	}
  
	else
      
	{
      
		cout<<"No answer!";
      
		return 0;
      
	}
  
	if (ans1==ans2)
      
	{
      
		printf("x1=x2=%.5lf",ans1);
      
	}
  
	else
      
	{
      
		if (ans1<ans2)
          
		{
          
			printf("x1=%.5lf;x2=%.5lf",ans1,ans2);
          
		}
      
		else
          
		{
          
			printf("x2=%.5lf;x1=%.5lf",ans2,ans1);
          
		}
      
	}
  
	return 0;
  
}

为啥不过？

求助神犇