#include <stdio.h>
#include <math.h>


/* Find roots in the quadratic equation a * x*x + b * x + c = 0.
   Assume as a precondition that a is not zero                    */
void solveQuadraticEquation(double a, double b, double c, 
                            int *numberOfRoots, double *root1, double *root2){
  double discriminant;

  discriminant = b * b - 4 * a * c;

  if (discriminant < 0){
    *numberOfRoots = 0;
  }
  else if (discriminant == 0){
    *numberOfRoots = 1;
    *root1 = -b/(2*a);
  }
  else{
    *numberOfRoots = 2;
    *root1 = (-b + sqrt(discriminant))/(2*a);
    *root2 = (-b - sqrt(discriminant))/(2*a);
  }
}   

int main(void) {
  double a, b, c, firstRoot, secondRoot;
  int numberOfRoots;
  printf("Enter coeficients a, b, and c: ");
  scanf("%lf %lf %lf", &a, &b, &c);

  if (a != 0){
    solveQuadraticEquation(a, b, c, &numberOfRoots, &firstRoot, &secondRoot);  
    if (numberOfRoots == 0)
      printf("No roots\n");
    else if (numberOfRoots == 1)
      printf("One root: %f\n", firstRoot);
    else 
      printf("Two roots: %f and %f\n", firstRoot, secondRoot);
  }
  else
    printf("The coeficient a must be non-zero");

  return 0;
}