2015年第七周图形用户界面（GUI）应用开发

#include<iostream>
#include<cmath>
usingnamespace std;
int main( )
{
float  a,b,c,x1,x2;
cin>>a>>b>>c;
if ((b*b-4*a*c)>=0)
{
if((b*b-4*a*c)>0)
{
x1=(-b+sqrt(b*b-4*a*c))/(2*a);
x2=(-b-sqrt(b*b-4*a*c))/(2*a);
cout<<"两个不相等的实根分别是：x1="<<x1<<",""x2="<<x2<<endl;
}
else
{
x1=-b/(2*a);
cout<<"两个相等的实根，x1=x2="<<x1<<endl;
}
}
else
cout<<"方程无实根"<<endl;
return 0;
}