More about pionter and array

#include <stdio.h>


void strSort(u_char **a, int n);

typedef unsigned char u_char;
#define SIZE 5
int main() 
{
  int i,j;
  
/*   for (i = 0; i != 0; i < 2) */
/*     i++; */
/*   printf("%d\n", i); */

  char* a[2] = {"abc", "ef"};
  
  for (i = 0; i < 2; i++){
    
    for (j = 0; j < 3; j++) 
      printf("%x, ", &a[i][j]);  
    printf("\n");
  }
  

  char **pa = a;
  
  char **p2 = pa + 1;
  
  printf("%x, ", a);
  printf("%x, ", pa);
  printf("%x \n", p2);

  printf("%x, ", *p2 - 1);
  printf("%x, ", p2[-1]);
  printf("%x,\n", p2[0]);
  
  printf("%x, %x\n", *p2[-1] + 1, *p2[0]+1);

  printf("%x, %x\n", *(p2[-1] + 1), *(p2[0]+1));

///
  char b[2][3] = { "aa", "bb"};
  
  char (*pb)[3] = b;

  printf("%c,  %c", pb[0][1], (*(pb + 1))[1]);


////

  u_char *tobesort[SIZE] = {"cd", "ab", "ef", "ac", "dg"};
  
  strSort(tobesort, SIZE);
  for (i = 0; i < SIZE; i++)
    printf("%s, ", tobesort[i]);
  printf("\n");
  return 0;
  
}

#define swap(a, b, c) c = a, a = b, b = c

void strSort(u_char **a, int n)
{
  /* insertion sort of string */
  
  u_char **aj, **ak;
  u_char *s, *t, *tmp;
  
  
  for (aj = a+1; n-- > 1; aj++)
    for (ak = aj; ak > a; ak--) {
      for (s = ak[0], t = ak[-1]; *s && *t ; t++, s++)
        if (*s != *t)
          break;
      if (*s >= *t)
        break;
      swap(ak[0], ak[-1], tmp);
    }
}