A nice trick with symmetric array

aymmarr.c

static char digits[19] = { '9', '8', '7', '6', '5',
	'4', '3', '2', '1','0', '1', '2', '3', '4', '5',
	'6', '7', '8', '9' };

static const char* zero = digits + 9;

printf( "%c\n", zero[-1] );

看的太少了，奇技淫巧。