program to solve quadratic equation through c

program to solve quadratic equation through c
#include<stdio.h>
#include<math.h>
int main(){
  float a,b,c,d,real,imag,r1,r2;
  int k;
  printf("enter the values of a,b and c:");
  scanf("%f%f%f",&a,&b,&c);
  d=(b*b)-(4*a*c);
  if(d<0)
    k=1;
  if(d==0)
    k=2;
  if(d>0)
    k=3;
  switch(k){
case 1:
 printf("\n The roots are complex");
 real=-b/(2*a);
 imag=(sqrt(-d))/(2*a);
 printf("\n One root is %f+%f*i \n",real,imag);
 printf("\n Another root is %f-%f*i \n",real,imag);
 break;
case 2:
 printf("\n The roots are equal");
 printf("\n The root is %f",(-b/2*a));
 break;
case 3:
 printf("\n The roots real and unequal");
 r1=(-b+sqrt(d))/(2*a);
 r2=(-b-sqrt(d))/(2*a);
 printf("\n one root is %f",r1);
 printf("\n one root is %f",r2);
 break;
  }
  return(0);
}