4 #define LENGTH(vars) (sizeof(vars) / sizeof(vars[0]))
5 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
7 #define MIN(a, b) ((a) < (b) ? (a) : (b))
8 #define MAX(a, b) ((a) > (b) ? (a) : (b))
11 void *xmalloc(size_t size
);
12 void *xerror(char *errmsg
);