һԪ

来自「C语言相关程序」· 代码 · 共 37 行

/*求一元二次方程的根*/
#include<iostream.h>
#include<math.h>
void main()
{
	float a,b,c,disc,x1,x2,real,imag;
	cout<<"please input a,b,c:"<<endl;
	cin>>a>>b>>c;
	if(a==0)
	{
		if(b==0)
		cout<<"the equation wu jie."<<endl;
		else
			cout<<"the equation de jie wei:"<<-c/b<<endl;
	}
	else
	{
	disc=b*b-4*a*c;
	if(disc==0)
		cout<<"the equation has two equal roots:"<<-b/(2*a)<<endl;
	else if(disc>0)
		{
			x1=(float)(-b+sqrt(disc))/(2*a);
			x2=(float)(-b-sqrt(disc))/(2*a);
			cout<<"the equation has distinct real roots:"<<endl;
			cout<<"\nx1="<<x1<<"\nx2="<<x2<<endl;
		}
		else
		{
			real=-b/(2*a);
			imag=(float)sqrt(-disc)/(2*a);
			cout<<"the equation has complex roots:"<<endl;
			cout<<"x1="<<real<<"+"<<imag<<"i"<<endl;
			cout<<"x2="<<real<<"-"<<imag<<"i"<<endl;
		}
	}
}