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Errata in Puzzle GP 2020 Round 1 instructions booklet

For puzzle 11 (Modes), there appears to be errata in the instruction booklet: The stated example answer is "BAAC,CBC", however the graphics and instructions appear to indicate this should be "BAAC,CBB".

5. Compass: The clue numbers are awfully small in the example, could you make sure those are readable in the competition booklet?
7. Battleships (Phrase): Might a suggest replacing the phrase letter with: "The letters in the ship parts spell the given phrase in reading direction (left to right row by row from top to bottom)." And clarify whether spaces in the phrase have any significance. E.g., could there be a horizontal ship of length 3 reading "EBE"?
16. Tera XX: Why can't the bottom row read 4760?
16. Tera XX: I believe the base puzzle type is called "Terra X" (double r), would be nice to fix this.
17. Summon: Please don't call this plain "Summon", because Summon has a no-touch rule. Something like "Summon [may touch]", perhaps?
19. Hideout Fences: I think the rules would be clearer with something like "in that direction".
20. Japanese Sums: Will all rows and columns be clued. And/or, is a row/column without any givens unrestricted, or must it be all empty?

9. Skyscraper Sums - I'm not sure the regular "Skyscraper Clue Examples" graphic is hugely helpful here - might it be possible to adapt it so that instead of 3/2 on the left/right, you have 8 = (1+3+4) / 6 = (2+4) ?

11. Modes - Is it possible to display either the total number of cells in the grid, or else equivalently the number of times each symbol has to appear.

I also have a question: is it possible for the set to have duplicated symbols - for example {A,A,B}, so that A's appear twice as frequently as B's? (the formal mathematical interpretation of a set would appear to rule this out)

13. Slitherlink (Out-Liars) - this is more my personal taste, but it seems a bit odd to state some rules in the first paragraph as (implicitly) correct in the first paragraph, and then state in the second that actually this interpretation is sometimes incorrect. Perhaps something like:

"Clues inside cells of the grid have one of two meanings, depending on whether they are inside or outside of the loop. Clues N inside the loop indicate the corresponding cell has N loop segments along its edges. Clues outside the loop indicate the corresponding cell has either N+1 or N-1 loop segments along its edges.

Similarly for 14. Fillomino (off by one) - I would much prefer it if you said something like each area in the grid must only contain numbers that are either one higher or one lower than the area in question. There is something unsatisfying in stating up front that numbers in the grid are equal to areas, and then directly contradicting this later by saying actually for this type the numbers are all wrong.

There seems to be an error in the 10.Index Sums instructions :
- each number *above* is the sum of the *column* numbers
- each number *to the left* is the sum of the *row* numbers
-> Considering the example, I think *column* and *number* should be reversed ?

I think the wording should be beyond rather than behind.

Hi folks,
I've already played the puzzles and it concerns me that it hasn't been made any corrections or modifications of instructions according to posts here.

My competition booklet also includes these point values (that differ from IB):
1.Product Lines 11 (10)
2.Word Search (Count) 13 (11)
3.Arithmetic Square 14 (14)
4.Heyawake 11 (14)
5.Compass 21 (15)
6.Minesweeper 17 (17)
7.Battleships (Phrase) 31 (17)
8.Doppelblock Skyscrapers 24 (22)
9.Skyscraper Sums 31 (30)
10.Index Sums 16 (16)
11.Modes 30 (38)
12.Scrabble 47 (39)
13.Slitherlink (Out-Liars) 52 (51)
14.Fillomino (Off-By-One) 59 (52)
15.Yajilin (Regions) 60 (55)
16.Tera XX 61 (59)
17.Summon 57 (67)
18.Nanro 88 (88)
19.Hideout Fences 97 (97)
20.Japanese Sums 108 (132)


I can’t make sense of the hideout fences example.
Am i just tired or is it inaccurate?

The example seems fine. E.g. the 5 in the first row is satisfied because the 2 in column 1, the 1 in column 3 and 2 in column 4 hide directly behind the fence (and sum up to 5).

Eugene Porter's picture

Can anyone help me with a complete solution to the Yajilin. I am truly stuck....

I uploaded a video of my solve of this puzzle here: (Low quality but maybe you can make out the solution? Also it's not a particularly precise solve.)

I've also recorded a solution to this puzzle, with some commentary here:

Eugene Porter's picture

Thanks for the quick and dynamic responses !!