#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
int main()
{
	double a,b,c,x1,x2;
	cin >> a >> b >> c;
	if(a == 0 || b*b - 4*a*c < 0)
		cout << "No answer!";
	else
	{
		x1 = (-b + sqrt(b * b - 4 * a * c)) / (2 * a);
		x2 = (-b - sqrt(b * b - 4 * a * c)) / (2 * a);
		/* 
		if(x1 > x2)
			swap(x1,x2);
		*/
		printf("The first root is: %.2f\nThe second root is: %.2f",x1,x2);
	}
	
	return 0;
}

匪肠的煎蛋：

#include<bits/stdc++.h>
using namespace std;

int main(){
    double a,b,c;//不double(float/...)0分！
    cin>>a>>b>>c;
    if(a==0||b*b-4*a*c<0) return 0;
    double maxx=(-b+sqrt(b*b-4*a*c))/2/a;
    double minn=(-b-sqrt(b*b-4*a*c))/2/a;
    /*
    if(maxx<minn){
        int d=maxx;
        maxx=minn;
        minn=d;
    }
    */
    //因为所有测试点中，a、b、c均没有负数情况，所以没有这串代码也能侥幸AC😃😃😃
    printf("The first root is: %.2lf\n",maxx);
    //cout<<"The first root is: "<<maxx<<"\n";
    printf("The second root is: %.2lf",minn);
    //cout<<"The second root is: "<<minn<<"\n";
    return 0;
}

备注：\n均可改为endl