What is inverse function to XOR?

A.N.R.I picture A.N.R.I · Jan 11, 2013 · Viewed 94.6k times · Source

There is XOR function in Java - a^b

For exemple: 5^3 = 6

Can you tell me inverse function? If I have 6 and 3 can i get range of numbers which include number 5?

Answer

Veger picture Veger · Jan 11, 2013

The inverse is XOR!

If you have:

c = a^b;

You can get a or b back if you have the other value available:

a = c^b; // or b^c (order is not important)
b = c^a; // or a^c

For example if a = 5, b = 3 (and thus c = 6 as you mentioned) you get:

b=0011 (3)            a=0101 (5)
c=0110 (6) XOR   or   c=0110 (6) XOR
----------            ----------
a=0101 (5)            b=0011 (3)