Dr. Sudoku Prescribes #107 – 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: Mirror
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 = 0:40, Master = 0:50, Expert = 1:10
Solution: PDF
Is this the easiest puzzle to ever pop up on this site?
Possibly, but it is Monday, and its main step is non-trivial.
Scott, for a beginner your comment is the most helpful of the others so far. From the other comments one gets the impression that only a simpleton would need to spend time on it when in fact, as you point out, the main step needs a bit of thinking.
The critical position is reached after inserting a ship segment at C5 and filling in the waters:
1 2 3 4 5 6
+-------------
A | . . . _ _ _ 2
B | _ _ _ _ T _ 1
C | . . . _ * _ 2
D | . . . _ . _ 1
E | . . . . . . 3
F | . . . . . . 1
2 1 2 1 3 1
Here are two possible approaches from this position:
(1) D5 cannot be a segment. If it were, that would force a second invalid cruiser in E1-E3. Therefore D5 is water. The only position to place the cruiser is E4-E6. The rest is easy.
(2) E4 cannot be water. If it were, F4 would be a segment, row E then gets filled with segments, closing off row D. Therefore E4 is a segment. This leads to placing the cruiser at E4-E6. The rest is easy.
My guess is yes. I don’t recall ever solving a GM puzzle in under one minute before this one.
The first Masyu we released (#25) would have been time rated to 0:30 and 0:40 with the new standards introduced around puzzle #54 and is still our easiest puzzle. No other puzzle has lower median averages to this point, but a few Mondays are pretty close at 1 minute.
I can do this mentally..dun need 2 print it out..nice puzzle..thanks
2:07 s