Here’s a Crystal Mine puzzle, as practice for the upcoming British GP.
Rules Draw a path connecting the two arrows by shading some cells, such that all black circles are on the path, and such that no full two-by-two square of cells is used by the path.
Or see the instruction booklet.
Feels like anything can happen with coded puzzles… Here’s one that’s probably of medium difficulty as far as coded corals go, though the puzzle type seems to be inherently difficult.
Rules Map the letters to distinct positive numbers, and solve the resulting Coral puzzle: Shade some cells, such that all shaded cells are connected by edge, such that no 2-by-2-square is fully shaded, and such that all unshaded cells are connected to the puzzle border by edge. For clued rows and columns, the clues give the lengths of all connected blocks of shaded cells, in any order.
Or see the instruction booklet.
Here’s another Maximal Lengths puzzle.
Here’s a Prime Place puzzle, another type from the upcoming GP round. Finally a type that forces me to deal with rendering irregular grids! I wonder if we’ll have a hex grid in one of the next rounds?
Rules Place a number between 1 and 4 into each cell, such that each number occurs exactly four times. The digit sum of each horizontal or vertical word must be prime. The digit sum of a diagonal word is prime precisely if that word is marked with a gray diagonal. Here, a word is a maximal straight line of connected cells; words may have length 1.
Or see the instruction booklet.
Here’s another GP preview puzzle, a nice and easy Maximal Lengths. (There’s a harder one in the queue.)
Rules Draw a loop that visits each cell, such that the longest loop segment in clued rows or columns is equal to the clue. (Length is equal to the number of crossed grid lines.)
Or see the instruction booklet.
The Czech round of the puzzle GP will take place next week, the instruction booklet has been posted. Here’s a practice puzzle for one of the types.
Rules Place numbers from 1 to 6 in some cells so that no number repeats within a row or column. For rows and columns that have clues given on the outside, these numbers correspond to all sums of blocks of adjacent digits within that line, in the correct order. Furthermore, draw a loop that visits all cells without a number, passing horizontally and vertically from cell centre to cell centre.
One more GP practice puzzle.
Rules Place a number in each cell. The numbers within an area go from 1 to the size of that area, with consecutive numbers horizontally or vertically adjacent. Cells with equal numbers (necessarily from different areas) must not touch, not even diagonally.
Or see the instruction booklet.
Another practice puzzle for the GP.
Rules Fill the grid with numbers from 1 to 6 such that every row and column contains all numbers. The numbers represent skyscrapers of the given height. There is a gray shadow at the south edge of a cell if some skyscraper further south in that column would throw a shadow onto the roof of the skyscraper in that cell, with the sun shining at a 45º angle. Similarly, a shadow on the west edge corresponds to sunshine from the west.
Or see the instruction booklet.
Here’s a small practice puzzle for one of the new (to me) types at next weekend’s Japanese round of the puzzle GP.
Rules Group some circles into boxes, such that each box contains two or three circles, such that all circles within a box are connected by edges within that box, and such that edges don’t connect circles that belong to different boxes of the same size. Furthermore, all black circles must be boxed.
Maybe Puzzles 