A ^ 0 == A
A ^ A == 0
A ^ B == B ^ A
(A ^ B) ^ C == A ^ (B ^ C)
(3) and (4) together mean that the order in which numbers are xor
ed doesn't matter.
Which means that, for example, A^B^X^C^B^A^C
is equal to A^A ^ B^B ^ C^C ^ X
.
Because of the (2) that is equal to 0^0^0^X
.
Because of the (1) that is equal to X
.
I don't think there are any specific keywords that can help you to identify such problems. You just should know above properties of XOR.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…