void func1(unsigned char n) {
int i;
for(i=0;i<n;i++) {m[i]=i; printf("m[%i] = %i\n",i, m[i]);}
}

void func2(unsigned char n) {
int i,j
for(i=1;i<=n;i++) {j=m[n-i]; m[n-i]=m[i-1]; m[i-1]=j;}
if(n^1) m[n/2] = 255;
for(i=0;i<n;i++) printf("m[%i] = %i\n",i, m[i]);
}

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

unsigned char m[256], n, i;
unsigned int   x;

void init_array(unsigned char n);
void init_array1(unsigned char n);
void print_array(unsigned char n);
void print_array1(unsigned char n);
void invert_array(unsigned char n);
void invert_array1(unsigned char n);

void main() {
  do {
    printf("Enter N = "); scanf("%d", &x);
  }
  while ((x == 0) || (x > 256));
  n = (char)(x-1);
  init_array(n);
  //init_array1(n);
  print_array(n);
  //print_array1(n);
  //invert_array(n);
  invert_array1(n);
  print_array(n);

  printf("\n\nPress any key to end..."); x = getch();
}

void init_array(unsigned char n) {
  for (i = 0;;i++){
    m[i] = i;
    if (i == n) break;
  }
}

void init_array1(unsigned char n) {
  while(1) {
    m[n] = n;
    if (n == 0) break;
    n--;
  }
}

void print_array(unsigned char n) {
  printf("\n---------------------------------");
  for (i = 0;;i++){
    printf("\nm[%d] = %d", i, m[i]);
    if (i == n) {
      printf("\n---------------------------------\n");
      break;
    }
  }
}

void print_array1(unsigned char n) {
  printf("\n---------------------------------");
  do {
    printf("\nm[%d] = %d", n, m[n]);
    if (n == 0) {
      printf("\n---------------------------------\n");
      break;
    }
    n--;
  }
  while(1);
}

void invert_array(unsigned char n) {
unsigned char temp;
  for (i = 0; i <= n/2; i++) {
    temp = m[i];
    m[i] = m[n - i];
    m[n - i] = temp;
  }
  temp = n/2;
  if ((n - temp) == temp) {
      m[temp] = 255;
    }
}

void invert_array1(unsigned char n) {
unsigned char temp;
  for (i = 0; i <= n/2; i++) {
    temp = m[i];
    m[i] = m[n - i];
    m[n - i] = temp;
  }
  temp = n/2;
  if (!(n & 0x01)) {
      m[temp] = 255;
    }
}

void rearrange_array(unsigned char n)
{   unsigned char x = 0;
    unsigned char buf;

    if(n%2)
    {   array[(n-1)/2] = 255;
    {   x++;
     
    for (i=0; i<(n-x)/2; i++)
    {   buf = array[(n+x)/2 + i];
        array[(n+x)/2 + i] = array[(n+x)/2 - i - 1 - x]
        array[(n+x)/2 - i - 1 - x] = buf;
    }
}