/* Compute the two roots of a quadratic.  */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>     // Need to include math.h to use sqrt.


int main(void) {
  /* Variables for the three co-efficients of the 
     quadratic equation, and also for the two roots
     we will find.   */
  int a, b, c, s;
  double x1, x2;

  printf("Input the x^2 co-efficient a: ");
  scanf("%d", &a);
  printf("Input the x co-efficient b: ");
  scanf("%d", &b);
  printf("Input the constant term c: ");
  scanf("%d", &c);
  s = (b*b -4*a*c);
  if (a != 0) {
    if (s < 0) {
      printf("No real roots to this quadratic.\n"); 
    } else if (s == 0) {
      printf("Eq. has the repeated root %f.\n", -((double)b)/(2.0*a));
    } else {
      x1 = (-(double)b - sqrt(s))/(2.0*a);
      x2 = (-(double)b + sqrt(s))/(2.0*a);
      
      printf("The sols to %dx^2 +%dx +%d = 0 are ", a, b, c);
      printf("%lf and %lf.\n", x1, x2 );
    }
  }
  else if (b != 0) {
    x1 = -((double)c)/((double)(b));
    printf("1 sol to %dx^2 +%dx +%d = 0.\n", a, b, c);
    printf("It is %lf.\n", x1);
  }
  else if (c != 0) {           /* a AND b BOTH ZERO, c NON-ZERO  */
    printf("No sols to %dx^2 + %dx +%d = 0.\n", a, b, c);
  }
  else {                       /* a, b, c ALL ZERO */
    printf("Degenerate equation - everything is a solution!\n");
  }
  return EXIT_SUCCESS;
}