Case #1: 0.0000000000
Case #2: 1.0000000000
In the first test case, the only dog will enter the only cage. So the answer is 0.
In the second test case, if the first dog enters the cage of the same number, both dogs are in the cage of the same number,
the number of mismatch is 0. If both dogs are not in the cage with the same number of itself, the number of mismatch is 2.
So the expected number is (0+2)/2=1.