Author Archives: rob

Puzzle 70: Different Tapa

1 Reply

I’m meaning to write up a report on the recently finished 24th WPC. No official results yet, but Ken Endo won the individual competition before Ulrich Voigt and Palmer Mebane, and we (Florian, Philipp, Ulrich and I) took gold with the team in front of Japan, Germany B (inofficial) and USA.

Instead, here’s a puzzle I made in preparation for round 9, which consisted of various puzzles built around the idea of marking several areas that had to be filled differently.

tapa-different

Rules Solve as a standard Tapa. Additionally, each gray 2-by-2 square must be shaded differently. E.g., no two gray squares can have only the top left corner shaded.

There are 15 gray squares, the different shades of gray are only there to make it possible to tell the squares apart.

Edit Here’s an alternate rendering, due to edderiofer.

tapa-different-borders

Puzzle 68: Summawake

3 Replies

Here’s a practice puzzle I made for the German puzzle championships, which took place end of June. The puzzle is a Summawake, a variant of Heyawake that I haven’t seen before. I believed the competition puzzle (and the type) was due to Florian Kirch. It’s actually due to Ulrich Voigt! The instruction booklet has an example. summawake Rules Shade some cells, such that all unshaded cells are connected by edge, and that no two shaded cells share an edge. A horizontal or vertical stretch of unshaded cells may cross at most one area boundary. In addition, if there are any unshaded clues within an area, the number of shaded cells within that area must be equal to the sum of unshaded clues within that area.

Puzzle 67: Star Battle

1 Reply

I’ve made some star battle puzzles recently, for a series on croco-puzzle that’s starting today. Here’s one that turned out a bit hard. 3 stars.

doppelstern13

 

Rules Place stars in some cells, such that each row, column and area contains exactly 3 stars. Cells with stars must not touch, not even diagonally.

Puzzle 66: Japanese Sums with 0

5 Replies

Long time no post. I’ve been making puzzles for croco-puzzle recently, the ongoing Best of 24h series, in particular.

But, here’s a practice puzzle for the coming German GP round next weekend. It’s on the hard side — I’d be interested to hear if you find (a way around) the intended break-in.

japsum-0

Rules Shade some cells, and fill the remaining cells with digits from 0 to 6, such that no digit occurs more than once in each row or column. The numbers outside the grid indicate the sums of blocks of connected digits in the correct order. This includes single digits.

Example (digits 0-3)japanischesummennull-example

Puzzle 61 & 62: Neighbors

Leave a reply

Here are two neighbors puzzles, a type which features on next weekend’s Dutch round of the WPF Puzzle GP. This time there is plenty of practice material, see Richard’s comment on the GP forum.

I made the second one first, but it appears I broke or imagined some of the logic. It does seem to have turned out unique. Usually I wouldn’t post it, but maybe it’s good practice for dealing with an impenetrable puzzle? If you find a nice way through, do let me know.

neighbors2neighbors

 

Rules Place a digit between 1 and 3 in every cell, such that each row and column contains exactly three copies of each. A cell is shaded if and only if the digit that it contains is different from all orthogonally adjacent digits.