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

int main(void)
{
	int a,b,c,D,error;
     float f;

     do
     {
     printf("Input numbers a, b, c (ax^2+bx+c): ");
     scanf("%d %d %d", &a, &b, &c);
     if(error = (a==0 && b==0))
     	printf("error\n");
     } while(error);

     if(a != 0 && b != 0)
	{
	     D=b*b-4*a*c;
	     f=-b/(2*a);

	     if(D > 0)
     		printf("%15s%f+%f\n%20s%f-%f","two real roots: ",f,sqrt(D),"",f,sqrt(D));


     	else if(D < 0)
          	printf("%15s%f+i*%f\n%20s%f-i*%f","two complex roots: ",f,sqrt(-D),"",f,sqrt(-D));

          else
          	printf("%15s%f\n","multiple real roots",f);
     }

     else if(a==0 && b!= 0)
     	printf("degenerate : %f\n",-c/b);

     getch();
     return 0;
}