编辑代码

#include <iostream>
#include <cmath>
#include <cstdio>
using namespace std;
int main()
{
    double a=0, b=0, c=0, num1=0, num2=0, num3=0;
    cin >> a >> b >> c;
    if(a==0)
    {
        if(b==0)
        {
            if(c==0)
            {
                cout << "x属于R"；
            }
            else
            {
                cout << "x无解"
            }
        }
        else
        {
            num1=-c/b;
            cout << num1;
        }
    }
    else
    {
        if(b*b-(4*a*c)>=0)
        {
            num1=sqrt(b*b-(4*a*c));
            num2=(0-b+num1)/(2*a);
            num3=(0-b-num1)/(2*a);
            cout << "X1=" << num2 << " X2=" << num3;
        }
        else
        {
            cout << "x无解";
        }
    }
    return 0;
}