// Program to solve quadratic equation
// a*x*x+b*x+c=0
// Illustrates many if else statements to do many possible cases.

#include <iostream.h>
#include <math.h>

void main()
{
  double a, b, c;
  double discriminant;
  double soln1, soln2;
  double tolerance=1e-7;
  cout << "Enter coefficients a, b, c: ";
  cin >> a >> b >> c;
  // Special cases
  if (fabs(a)<tolerance){
    if (fabs(b)<tolerance){ // a=0, b=0
      if (fabs(c)<tolerance)
	cout << "Infinitely many solutions" << endl;
      else 
	cout << "No solutions" << endl;
    }
    else // Linear equation
      cout << "Solution is " << -c/b << endl;
  }
  else{ // Now have a!=0 and can use formula
    discriminant = b*b-4*a*c;
    if (discriminant<0)
      cout << "No solutions" << endl;
    else if (fabs(discriminant)<tolerance)
      cout << "Solution is " << -b/(2*a) << endl;               
    else{
      soln1=(-b+sqrt(discriminant))/(2*a);
      soln2=(-b-sqrt(discriminant))/(2*a);
      cout << "Solutions are " << soln1
	   << ", " << soln2 << endl;
    }
  }
}