#include <stdio.h>

int main(int argc, char** argv) {

  // Basic example of array with initialization
  int basic[20] = { 1, 2, 3, 4, 5};  // Note: rest will be set to zero
  printf("Basic array: { ");
  int index;
  for (index = 0; index < 20 ; index++) {
    printf(" %d,", basic[index]);
  }
  printf("}\n");


  int size = 10;
  int c[size]; // Note: using a variable as the array size is a recent feature

  // The following is wrong!!!
  c[12] = 23; // BUG! Array out-of-bounds
  printf("%d\n",c[12]); // BUG! Array out-of-bounds
  // The above are bugs! But they may remain silent.
  // The compiler does not check array bounds.
  // There are no explicit runtime checks either.
  // If you are lucky, you will get a segmentation fault
  // Often, out-of-bounds errors can go undetected for a long time
  // To avoid bugs, we must remember the size of the array
  // and always check bounds explicitly


  // An array is just a group of memory locations
  int i;
  for (i = size-1; i >= 0 ; i--) {
    printf("%p\n",&c[i]);
  }

  // The name of the array corresponds to the address of the
  // beginning of the array
  printf("Array name: %p\n", c);


  // Two methods to access and update elements of the array
  for (i = size-1; i >= 0; i--) {
    c[i] = 2*i;
    printf("c[i] is %d    ", c[i]);   // Preferred, more readable 
    printf("*(c+i) is %d\n", *(c+i)); // Possible

  }

  // We can create additional pointers to the array
  // This can be useful. For example, if we want to sort the elements of the array
  int *p = c;
  printf("Test %d\n", *p);
  p++;
  printf("Test %d\n", *p);

  return 0;
}