From the Foxger’s Den #4: Star Battle
or solve online (using our beta test of Penpa-Edit tools)
Theme: Author’s monogram
Rules: Standard Star Battle rules. Two stars per row, column, and region.
Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. Enter these numbers as a single string with no separators.
Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:30, Expert = 9:00
Solution: PDF
Note: Follow this link for other classic Star Battles and this link for Star Battle variations. If you are new to this puzzle type, here are our easiest Star Battles to get started on. More Star Battle puzzles can be found in The Art of Puzzles, in the book Star Battle by JinHoo Ahn, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.
I bifurcated at the beginning around the G/U region… is that the intended break in, or is there a non-trial and error approach that I’m missing. I really suck at these.
It’s tricky opening, which then barrels down into a really easy solve. I don’t have a really nice deduction. The way I did it, is as follows.
1) The G and U shape for you to conclude that both the G and U need both their Stars in the same row.
2) The U shape needs one Star in C5, which means the shape between the U and F shape needs atleast one star in C6.
3) This forces the F shape to have at least one Star in R4, as otherwise it would block the shape between U and F having a Star in C6.
4) As F needs at least one Star in R4, G can’t have both stars in R4. Therefore they both have to be in R7.
I hope this is clear. It’s the way I made the necessary deduction. It’s for me also the cleanest way, but maybe there’s an easier/nicer way.
What I had was:
Start with your 1)
2) In either arrangement, the top 4 rows of the long cell must be eliminated either because there was a star next to it, or that the row is filled with 2 stars.
3) This forces the long cell, and then only 1 of the 2 arrangement would give enough free space for F.
Of course, I saw this only after bifurcating, which was probably the easier solution.
I am not too good at these either but that is exactly where I broke in as well – I can resolve this down to two options for the G/U area, and one of them breaks logically about 2 or so “obvious placements” later (unless I guess your lookahead is better than mine. I’m terrible. Then it went pretty quickly, as they always seem to once you actually break in.
I’ve solved it twice and each time my first logical step ended up being this entire ping-pong in my head: The G is either both up top or both down below, but if both up top then both F are on the left but one star must be in C6 in the region immediately to the left of the F. So G is both down below.
While I really liked the effect of the n on the G as a solver as a seed to consider for future construction, I know that those who can’t visualize the whole thing may choose to bifurcate. A couple of the other testers definitely did.
This seems to be what I ended up doing, though not in my head. Grant has confirmed that was his approach as well.
Managed to achieve Master level.
Very beautiful start, once G is solved the rest will go very easily.
The 7 Streak continues for me
7:28 mins.
Had fun solving the entire puzzle.Lovely puzzle!
I did the start more or less in the same way as described. After deducing that the 2 stars in G have to be either both up or both down i tried the wrong case first and i obtained a contradiction in not more than 3 steps.That helped a lot.And then it was a very smooth solve.
06:33. So I tried to find a logical solution (didn’t found one; has to resort to bifurcating for first 8 stars before finding a contradiction). I suppose I should have gone through the bifurcation earlier, instead of after 4-5 minutes into the puzzle. Nice puzzle.
Wow, I can’t believe the last 2 puzzles were all Grant’s. His puzzles in his blog are mostly easy puzzles, without opening this tough or a rather narrow solving path like yesterday’s. 😛 I’m hoping for something even more difficult for Saturday (aka today) 😀
Nice! I did find the break-in (finally!). I definitely could have gotten there faster by bifurcating, but it was nice and satisfying to not do that.
Thanks, Grant!
Online version: [EDIT: Removed as we added our own official link to post]