C program to find the second largest and second smallest form set of elements

/* Write a C program to accept a list of data items and find the second largest and second smallest elements in it. And also computer the average of both. And search for the average value whether it is present in the array or not. Display appropriate message on successful search. */

#include <stdio.h>

void main ()
{
  int number[30];
  int i,j,a,n,counter,ave;

  printf ("Enter the value of N\n");
  scanf ("%d", &n);

  printf ("Enter the numbers \n");
  for (i=0; i<n; ++i)
  scanf ("%d",&number[i]);

  for (i=0; i<n; ++i)
  {
for (j=i+1; j<n; ++j)
{
if (number[i] < number[j])
{
a        = number[i];
number[i] = number[j];
number[j] = a;
}
}
  }

  printf ("The numbers arranged in descending order are given below\n");
  for (i=0; i<n; ++i)
  {
printf ("%d\n",number[i]);
  }

  printf ("The 2nd largest number is  = %d\n", number[1]);
  printf ("The 2nd smallest number is = %d\n", number[n-2]);

  ave = (number[1] +number[n-2])/2;
  counter = 0;

  for (i=0; i<n; ++i)
  {
 if (ave == number[i])
 {
++counter;
 }
  }
  if (counter == 0 )
printf ("The average of %d  and %d is = %d is not in the array\n", number[1], number[n-2], ave);
  else
printf ("The average of %d  and %d in array is %d in numbers\n",number[1], number[n-2], counter);
}           /* End of main() */

/*-------------------------------------------------------
Output
Enter the value of N
6
Enter the numbers
30
80
10
40
70
90
The numbers arranged in descending order are given below
90
80
70
40
30
10
The 2nd largest number is  = 80
The 2nd smallest number is = 30
The average of 80  and 30 is = 55 is not in the array


-------------------------------------------------------*/