Thread: Segmentation Error / Bus Error in ANSI

I keep getting segmentation or bus errors based on this code:
It compiles fine and the output is just like the ones in the assignment.

Code:

/* */
#include <stdio.h>

int main(void)
{
  int cases,a;
  scanf("&#37;d",&cases);
  float student_percentage[cases];
  for(a=0; a<cases; a++)
          {
               int students;
               scanf("%d",&students);
               int b,c,d;
               float total,average;
               float num_of_students = 0;
               float grades[students];
               for(b=0; b<students; b++)
                        {
                                   scanf("%f",&grades[b]);
                        }
               total = 0;
               for(c=0; c<students; c++)
                        {
                                    total = total + grades[c];
                        }
               average = total / students;
               for(d=0; d<students; d++)
                                            {
                                                        if(grades[d] > average)
                                                                     {
                                                                               num_of_students++;
                                                                              }
                                                        else { };
                                            }
               student_percentage[a] = num_of_students / students;
               }
  int x;
  for(x=0; x<cases; x++)
  { 
           printf("%.3f%%\n",student_percentage[x]*100); 
           }
  return 0;
}

Thanks!