[완료] C 코드 해석좀 부탁드립니다.

typedef unsigned char	u8;
typedef unsigned int	u32;
 
static const u8 pc1[56] = {
        56, 48, 40, 32, 24, 16,   8,   0, 
        57, 49, 41, 33, 25, 17,   9,   1,
        58, 50, 42, 34, 26, 18,  10,   2,
        59, 51, 43, 35, 62, 54,  46,  38,
        30, 22, 14,  6, 61, 53,  45,  37,
        29, 21, 13,  5, 60, 52,  44,  36,
        28, 20, 12,  4, 27, 19,  11,   3
};
 
static const u32 bytebit[8] =
{
        0200, 0100, 040, 020, 010, 04, 02, 01
};
 
void main()
{
    u32 j, l, m;
    u8 pc1m[56], pcr[56], key[8] = "12345678";
 
    for (j = 0; j < 56; j++) {
        l = (u32) pc1[j];
        m = l & 7;
        pc1m[j] = (u8)((key[l >> 3U] & bytebit[m]) == bytebit[m] ? 1 : 0);
}