## Archive for the ‘**Puzzles!**’ Category

## Puzzle 25: Oasis

Rules (from the WPC 2016 instruction booklet): “Shade some cells in the grid. Shaded cells cannot touch each other orthogonally. All unshaded cells must be orthogonally interconnected. Unshaded cells cannot form a 2×2 square. Cells with circles cannot be shaded. A number indicates how many other numbers or circles can be reached from that cell by passing only orthogonally through empty unshaded cells (it cannot pass a shaded cell nor a cell with a number / circle).”

Notes: I think Oasis is the best new puzzle type introduced at the 2016 WPC. It feels very original, the rules are intuitive and relatively simple, and there’s tons of potential for interesting local and global logic (as demonstrated in the GP round 2 Oasis puzzles, which I highly recommend). I’d love to see others construct this type; let me know if there are other examples out there (the only other one I know of is on Walker’s blog).

Also, this was indeed the 25th WPC.

## Puzzle 24: Trimino Divide

This puzzle was made for WPC 2016 practice. Rules (from the IB): “Divide the grid along the given lines into triminoes. Each trimino is formed by three orthogonally adjacent cells. When there is a cross between two triminoes, they must be of a different shape. When there is a triangle between two triminoes, they must be of the same shape, but different orientation. When there is a dot between two triminoes, they must be of the same shape and the same orientation. Symbols always lie on a trimino border, not inside a trimino.”

## Puzzle 23: Black Hole Tapa

Rules (copied from the TVC instruction book): Follow regular Tapa rules. Additionally, each row/column must contain N Black Holes. Black Holes must be placed on the Tapa wall. For the purposes of surrounding clues, a cell with a Black Hole counts as M consecutive shaded cells instead of 1. Black Holes may touch each other. N and M will be given in Puzzle Booklet.

Also, in this puzzle, one of the clues has a 0 in it. I think the meaning of this should be natural, but just to be precise, the 0 must correspond to a non-empty group of black cells whose total length (adjusted for black holes) is 0.

Edited to add one more clarification: Even though the black holes count as 0 for clue purposes, they still count as black squares for everything else (black holes count for connectivity, you can’t have a 2×2 square of black holes, etc.)

Notes: Well, I suppose I’m still alive. 😛

After going to the WPC (I’m currently writing a recap and hope to have it finished at some point), I’ve been motivated to get back into making puzzles after I basically had no time at all the past year due to school/burnout. So, have some TVC practice! Although I’m not sure whether this puzzle is representative of a typical Black Hole Tapa, as M=0 is a little unusual heh.

## Puzzle 22: Nurikabe (pairs)

Rules from MellowMelon’s blog: This is a Nurikabe puzzle, with a twist. Every region of unfilled cells must contain exactly two numbers (instead of one) and have total size equal to the sum of the two numbers.

Notes: After a 3 month break, and thanks to a 2-hour long physics class, we’re back. 😀 Also, there’s no hidden valentine’s day theme or anything (I didn’t even know that it was valentine’s day until I saw students carrying around flowers today, heh). The 2s are, well, for puzzle 22, and feel free to count how many 2s there are.

On another note, I might post a more detailed mystery hunt recap sometime. Out of the logic puzzles I remember, Portals was amazing, Agricultural Operations was cool, A Regular Crossword was cute, and Random Walk was okay but had lots of trial and error. Palindrome was an awesome team to solve with, as usual!

## Puzzle 21: Skyscrapers Fillomino

Rules (from the Fillomino-Fillia 2 booklet): In addition to the usual rules, the numbers in the grid should be treated as building heights. Numbers on the outside of the grid tell how many buildings are visible when looking from that direction. A building obscures all buildings behind it whose height is equal to or smaller than itself.

Notes: This puzzle is brought to you by the numbers 1, 2, 3, 4, and 5.

If you haven’t done Fillomino-Fillia 2 yet, there’s still time! You can still start the test any time in the next 3 hours or so. And even if you don’t plan on competing, you should definitely do the puzzles afterwards, because they are amazing.

## Puzzle 20: Fillomino (no row/column repeats)

This is a Fillomino, with the added rule that in any row or column, all cells with the same number must be part of the same region. In other words, no two regions of the same size can share any row or column.

Notes: With three puzzles in three weeks, it seems like this blog might actually be revived after all. 😀

Also, in case you haven’t heard, Fillomino Fillia 2 will be held at LMI this weekend, and it’s definitely going to be awesome, so everyone reading this should do it! I might create and post some practice puzzles this week if I have the time.

## Puzzle 19: Looking for the Loop

Instructions (taken from the WPC): Draw a single closed loop in the grid by connecting horizontally and vertically neighboring cells. The loop can touch itself, but it cannot cross or overlap itself. Cells with numbers cannot be parts of the loop. Each number in the grid indicates how many of the eight neighboring cells are used by the loop.

Also, in this puzzle, the loop cannot go through any squares with an X (yeah, I know it’s sort of inelegant; looking for the loop is quite a bit more difficult than tapa-like loop when it comes to uniqueness).

Notes: I am currently attempting to stick to a one puzzle per week schedule. Let’s see whether I keep my promise next Monday/Sunday!