关于我把
N=(A−1)∗(B−2)∗(C−2)N=(A-1)*(B-2)*(C-2)N=(A−1)∗(B−2)∗(C−2)
分解了下面这个
N=A∗B∗C−2∗A∗B−2∗A∗C+4∗A−B∗C+2∗B+2∗C−4N=A*B*C-2*A*B-2*A*C+4*A-B*C+2*B+2*C-4N=A∗B∗C−2∗A∗B−2∗A∗C+4∗A−B∗C+2∗B+2∗C−4
az
