#+-+-+-+-+-+
+-+-+-+-+-+#

Edited by author 09.01.2021 01:54

Some implementation bugs I had

1. Some secret may become reachable several times from different sides when filling some area. Make sure that list of reachable secrtets does not overflow due to that.

2. If you test touching the secret along with testing walls, make sure you don't write something like that

if(!has_wall(...) || !has_wall(...))

where has_wall() returns true/false along with adding newly discovered secret to the list. The danger here is that if 1st operand of || is 'true', the 2nd one is not even evaluated according to C++ standard. So it might happen that some secret is not added to the list because 'has_wall' is not called due to free passage on the neighboring wall. But it's safe to replace boolean || with binary |. The latter is always evaluated for both operands even if the 1st one returns -1 (all ones).

It says:

The Secret is a regular junction (+) with one of the objects of special interest contained inside. This object of interest is accessible from any of the four sides of the junction.

As far as I understand, "the four sides of the junction" means left, right, up and down. In this case, the answer for the following test:

..+..
..+..
++#++
..+..
..+.#

should be

10
01

because there's no way we can reach the middle Secret. Meanwhile, a program that outputs

11
11

gets AC, while the one that outputs what I think is correct gets WA at 6th test.

The clarification that may help people having this problem is: one can access the Secret object not only from those 4 sides, but also diagonally.

My program solves all testes on forum
but has WA2.
After some experiments I established that test 2 has
form : xx+xx
       x#|#x
where symbols x are not important
It is obvious that secrets # mutually unreacheable
But experiments say that test has it's answer 11
                                              11

#+#
+#+
#+#

and

#|#
-#-
#|#

and

#-#
+#-
#+#

Realy fun problem:)
Memory/Time limit ballance

interesting, somebody can solve it without using STL(i mean not using something like deque)?