1.
char table[17] = "0123456789ABCDEF";

2.
16進位的0~F轉成0~15:
char hexchar_to_int[17] = "0123456789ABCDEF";
for (j = 0; j < 16; j++) {
            if (num[i] == hexchar_to_int[j])
                break;
        }