A.A1A1A1A2A2A2 B.A1A2A3A1A2A3 C.A2A2A2A1A1A1 D.A1A2A1A2A1A2
A.比特間插 B.奇偶比特效驗 C.比特間插奇偶效驗 D.奇偶效驗
A.鏈狀 B.樹形 C.星形 D.環(huán)形