/*
 * Program to calculate roots of a quadratic equation using
 * the quadratic formula.  For now, input is hard-coded.
 * This program contains a bug!
 */
#include <stdio.h>
#include <math.h>

void solve_and_print(double a, double b, double c);

int main(void) {
        solve_and_print(1, 0, -4);
        solve_and_print(1, 0, 4);
        solve_and_print(1, 0, 0);
	/* uncomment the next line to observe the bug in action */
        /* solve_and_print(0, 1, 4); */
        return 0;
}

/* print root(s) of a*x*x + b*x + c = 0, or message if none */
void solve_and_print(double a, double b, double c) {

        double discrim = b*b - 4*a*c;

        if (discrim > 0) {
                printf("two roots:  %g %g\n", 
                                (-b + sqrt(discrim))/(2*a),
                                (-b - sqrt(discrim))/(2*a));

        }
        else if (discrim == 0) {
                printf("one root:  %g\n", (-b) / (2*a));
        }
        else {
                printf("no roots\n");
        }
}