共24种
3×2×4=24
分别是
AABC ABAC BACA BCAA
AACB ACAB CABA CBAA
BBAC BABC ABCB ACBB
BBCA BCBA CBAB CABB
CCAB CACB ACBC ABCC
CCBA CBCA BCAC BACC
共24种
3×2×4=24
分别是
AABC ABAC BACA BCAA
AACB ACAB CABA CBAA
BBAC BABC ABCB ACBB
BBCA BCBA CBAB CABB
CCAB CACB ACBC ABCC
CCBA CBCA BCAC BACC