You are given two integer arrays source and target, each of length $2$, representing the starting position source and the destination position target of a bishop on an $8 imes 8$ chessboard.

In a single move, a bishop can move any number of squares along any diagonal direction without leaving the board.

Return the minimum number of moves needed to move the bishop from source to target. If it is impossible to reach target, return $-1$.

Constraints:

• source.length $=$ target.length $= 2$

• $1 \leq$ sr, sc, tr, tc $\leq 8$, where source $= [$ sr, sc $]$ and target $= [$ tr, tc $]$

• source $\neq$ target

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.