#AT2443. G - Tatami
G - Tatami
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G - Tatami
Score : $600$ points
Problem Statement
We have a grid with $H$ horizontal rows and $W$ vertical columns. We denote by square $(i,j)$ the square at the $i$-th row from the top and $j$-th column from the left.
We want to cover this grid with $1 \times 1$ tiles and $1 \times 2$ tiles so that no tiles overlap and everywhere is covered by a tile. (A tile can be rotated.)
Each square has 1
, 2
, or ?
written on it. The character written on square $(i, j)$ is $c_{i,j}$.
A square with 1
written on it must be covered by a $1 \times 1$ tile, and a square with 2
by a $1 \times 2$ tile. A square with ?
may be covered by any kind of tile.
Determine if there is such a placement of tiles.
Constraints
- $1 \leq H,W \leq 300$
- $H$ and $W$ are integers.
- $c_{i,j}$ is one of
1
,2
, and?
.
Input
The input is given from Standard Input in the following format:
Output
Print Yes
if there is a placement of tiles to satisfy the conditions in the Problem Statement; print No
otherwise.
3 4
2221
?1??
2?21
Yes
For example, the following placement satisfies the conditions.
3 4
2?21
??1?
2?21
No
There is no placement that satisfies the conditions.
5 5
11111
11111
11211
11111
11111
No