Okay,let’s consider that we can move to the parallel cell.

Now I’ll prove that this statement is wrong by CONTRADICTION!

lets consider these four cells.

Imagine that you are initially at cell ‘C’.

Now you move to Cell ‘D’ which is parallel to it.(which according to you can be considered as an optimal move)

Now from cell ‘D’,you have two choices–

->Either you can move to cell ‘B’.(when A is blocked). It takes two steps(C–D--B).

But you can also move from ‘C’ directly to ‘B’(1 move which is optimum).

–>From cell ‘D’,you can also move to cell ‘A’.(when B is blocked). that would be C–D--A(two moves).

You were initially at ‘C’(this could have been done in one move i.e C–A).

In either of the cases you see moving parallel is not optimum.

And if you cannot jump to the next block nor the diagonal. In that case,you cannot simply go beyond that.

I got AC for my solution at first attempt

You may check the code. It’s easy to understand - Solution

I hope you understand it.