I think this problem is not very hard and it's interesting.

Description:

You are given $$$2$$$ arrays $$$a$$$ and $$$b$$$ and the length of them is $$$n$$$.

• $$$1$$$, $$$3$$$, $$$5$$$, ......, $$$2 * n - 1$$$ is in $$$a$$$.

• $$$2$$$, $$$4$$$, $$$6$$$, ......, $$$2 * n$$$ is in $$$b$$$.

$$$\mathrm{Algorithm}\ 1:$$$

we use the array $$$mp_i$$$ is $$$i$$$ the distance to the $$$a_1$$$ or $$$b_1$$$.

We can enumerate the $$$i$$$ and the $$$j$$$, and the answer is $$