# AtCoder Grand Contest 007 review

I felt you need more invetiveness/creativeness in this contest, and it was difficult.

## A – Shik and Stone

Compared to ARC (regular contest), it is slightly difficult even from problem A.

The most elegant solution is to just check the number of ‘#’ is equal to $$W+H-1$$ or not as explained in Editorial.

However, I could not notice it so I checked that we can actually go using only right or down or not.

## B – Construct Sequences

You need to come up with one construction method which satisfies the 3 conditions.

Editorial way is much more easier than below construction.

## C – Pushing Balls

Since most of the participants could not solve it, I’ll skip this.

## D – Shik and Game

This algorithm takes $$O(N^2)$$, which pass only 600 points.