a006. 一元二次方程式 | From: [218.173.130.42] | 發表日期 : 2010-07-28 00:17

#include <iostream>
#include <math.h>
using namespace std;

int main()
{
 double a,b,c,x1,x2,d;
 d = b*b-4*a*c;
 x1 = (-b+sqrt(d))/2/a;
 x2 = (-b-sqrt(d))/2/a;

 while(cin >> a >> b >> c){
  if(d>0)
   cout << "Two different roots x1=" << x1 << " , x2=" << x2 << endl;
  
  else if(d == 0)
   cout << "Two same roots x=" << x1 << endl;
  
  else
   cout << "No real root" << endl;
  
 }
 system("PAUSE");
 return 0;
}