C语言字符串另类用法的实现

#include <stdio.h>
#include <string.h>
int main(void)
{
 int num = 15 ;
 //26个字母 
 const char str[] = \"abcdefghijklmnopqlstuvwxyz\" ;
 //这个做法是将num这个十进制数通过取模转换为字母并输出，从程序看，即可知道是输出p 
 char a = str[num%26] ;
 printf(\"a=%c\\n\",a);
 return 0 ; 
} 

#include <stdio.h>
#include <string.h>
int main(void)
{
 int num = 15 ;
 char *str = \"abcdefghijklmnopqlstuvwxyz\" ;
 char a = str[num%26] ;
 printf(\"a=%c\\n\",a);
 return 0 ; 
} 

#include <stdio.h>
#include <string.h>
int main(void)
{
 int num = 15 ;
 //char *str = \"abcdefghijklmnopqlstuvwxyz\" ;
 char a = \"abcdefghijklmnopqlstuvwxyz\"[num%26] ;
 printf(\"a=%c\\n\",a);
 return 0 ; 
} 

#include <stdio.h>
int main(void)
{
 char *p = \"0123456789abcdef\" ;
 putchar(p[3]);
 //换行 
 putchar(\'\\n\');
 putchar(*(p + 3));
 putchar(\'\\n\');
 putchar(\"0123456789abcdef\"[3]);
 putchar(\'\\n\');
 putchar(*(\"0123456780abcdef\"+3));
 putchar(\'\\n\');
 return 0 ; 
}