The Puzzle Robot #8 – Battleships

Battleships by Serkan Yürekli

PDF

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

  • chaotic_iak says:

    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.

  • Moshe Rubin says:

    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.

  • skynet says:

    6:11

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