7569: [CSES Problem Set] Monsters
[Creator : ]
Description
You and some monsters are in a labyrinth. When taking a step to some direction in the labyrinth, each monster may simultaneously take one as well. Your goal is to reach one of the boundary squares without ever sharing a square with a monster.
Your task is to find out if your goal is possible, and if it is, print a path that you can follow. Your plan has to work in any situation; even if the monsters know your path beforehand.
Your task is to find out if your goal is possible, and if it is, print a path that you can follow. Your plan has to work in any situation; even if the monsters know your path beforehand.
Input
The first input line has two integers $n$ and $m$: the height and width of the map.
After this there are $n$ lines of $m$ characters describing the map. Each character is . (floor), # (wall), A (start), or M (monster). There is exactly one A in the input.
After this there are $n$ lines of $m$ characters describing the map. Each character is . (floor), # (wall), A (start), or M (monster). There is exactly one A in the input.
Output
First print "YES" if your goal is possible, and "NO" otherwise.
If your goal is possible, also print an example of a valid path (the length of the path and its description using characters D, U, L, and R). You can print any path, as long as its length is at most $n \cdot m$ steps.
If your goal is possible, also print an example of a valid path (the length of the path and its desc
Constraints
$1≤n,m≤1000$
Sample 1 Input
5 8
########
#M..A..#
#.#.M#.#
#M#..#..
#.######
Sample 1 Output
YES
5
RRDDR