The Puzzle Robot #8 – Battleships
or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between ship placement and shading modes. In ship placement mode, right click gives sea, left click gives circle/square, left click and drag for rounded ships.)
Theme: Whirlpool
Rules: Standard Battleships rules. Use the indicated fleet.
Answer String: For each row from top to bottom, enter the number of the first column from the left where a ship segment appears. If the row is empty, enter 0. Enter these numbers as a single string with no separators.
Time Standards (highlight to view): Grandmaster = 1:25, Master = 2:15, Expert = 4:30
Solution: PDF
01:52.
Definitely a unique aesthetic theme, and the solving path is also quite unusual (perhaps due to the theme). And definitely not a Monday heh. But nice.
Nice puzzle, and not difficult. Here are some solving insights:
(1) Note how the row counts add up to 20. That means that all other rows have a count of 0, i.e., contain only water. So rows C and G are all waters. This is not critical to the solving process, but it simplifies things down the road.
(2) Easy rules get us to the following board:
1
1 2 3 4 5 6 7 8 9 0
+---------------------
A | _ _ _ _ _ _ _ _ _ _
B | _ _ _ _ _ _ _ O _ _ 1
C | _ _ _ _ _ _ _ _ _ _
D | _ . . * . . . _ T _ 6
E | _ . _ _ _ _ . _ M _ 2
F | _ * _ L R _ * _ B _ 5
G | _ _ _ _ _ _ _ _ _ _
H | _ * _ _ _ _ _ _ _ _ 1
I | _ . _ * . . . * R _ 5
J | _ _ _ _ _ _ _ _ _ _
4 3 2 1 2 4
(3) D2 and D7 cannot be waters, i.e., that would force a 5-segment ship, so they are segments:
1
1 2 3 4 5 6 7 8 9 0
+---------------------
A | _ _ _ _ _ _ _ _ _ _
B | _ _ _ _ _ _ _ O _ _ 1
C | _ _ _ _ _ _ _ _ _ _
D | _ * . * . . * _ T _ 6
E | _ . _ _ _ _ . _ M _ 2
F | _ * _ L R _ * _ B _ 5
G | _ _ _ _ _ _ _ _ _ _
H | _ * _ _ _ _ _ _ _ _ 1
I | _ . _ * . . . * R _ 5
J | _ _ _ _ _ _ _ _ _ _
4 3 2 1 2 4
(4) D5 must be a segment. Making it water would have filled E2 and E7 with segments, with too few segments.
1
1 2 3 4 5 6 7 8 9 0
+---------------------
A | _ _ _ _ _ _ _ _ _ _
B | _ _ _ _ _ _ _ O _ _ 1
C | _ _ _ _ _ _ _ _ _ _
D | _ * . * * . * _ T _ 6
E | _ . _ _ _ _ . _ M _ 2
F | _ * _ L R _ * _ B _ 5
G | _ _ _ _ _ _ _ _ _ _
H | _ * _ _ _ _ _ _ _ _ 1
I | _ . _ O _ . . * R _ 5
J | _ _ _ _ _ _ _ _ _ _
4 3 2 1 2 4
(5) The last insight needed is that the two remaining destroyers (i.e., two-segment ships) can only be placed in H2-I2 and I8-I9.
The rest is trivial.
6:11
@skynet: A penny for your thoughts on what you found difficult and how you solved it in the end?