C Program to Calculate Roots of a Quadratic Equation

#include<stdio.h>
#include<math.h>
main ()
{
    int a,b,c,r1,r2,x,y;
    float d;
    printf("enter the values of coefficients a,b,c\n");
    scanf("%d%d%d",&a,&b,&c);
    while (a == 0)
   {
        printf("reenter the value of a");
        scanf("%d",&a);
        printf("\n");
  }
  d = ( b * b ) - (4 * a * c);
  if(d==0){
       printf("roots are equal\n");
       printf("r1=%f  r2=%f  ", -b/(2*a),  -b/(2*a));
  }
  else if(d>0){
      printf("roots are real and unequal");
      printf("r1=%f r2=%f ,(-b + sqrt(d))/(2*a),(-b - sqrt(d))/(2*a) );
  }
  else{
     x = -b/(2*a);
     y = sqrt(d)/(2*a);
     printf("roots are imaginary.\n");
     printf("r1=%f r2=%f ",x+(i*y) , x - (i*y));
 }
}