Flashback #4 – Count Me In

It would be another 6 months until I finally authored my first online test. I met Mike Colloby during the Beijing International Sudoku Tournament in May 2011 and he introduced me to the newly-created United Kingdom Puzzle Association website. I was elated when he mentioned how he would love to offer more puzzles for his visitors. We discussed a possibility of an online test and the idea of Puzzle Cruise was born. Mike forwarded Puzzle Cruise to Alan O’ Donnell, who forwarded it to the world in July that year.

Logo as seen on the instructions booklet

Puzzle Cruise took roughly the same format as that time’s USPC: 300 points in two and a half hours and the dreaded 5 point penalty for each incorrect submission. I even included a Count Me In puzzle to imitate USPC more accurately.

UKPA, July 2011

Count Me In: Count the number of triangles of any size in this diagram. 

50 people submitted an answer and only 29 got it right. That’s a correct rate of 58%, by far the lowest of all the puzzles in the test. Can you figure out the right number of triangles in the picture?

Flashback #3 – Tents Reconstruction

This will be the last puzzle from my 2010 24HPC set that I’ll put here. I remember looking at the Puzzle Wiki page for ideas and found Tents Reconstruction. A good step to familiarize yourself with a puzzle type is to solve a lot of them or try constructing them. I’ve never seen this variant of Tents before so my only option was to go ahead and write some myself. I started small and came up with a basic 4×4, which became the example puzzle for the instruction booklet. I ramped up a few notches with a 5×5 then 6×6, 8×8 and ending at 10×10. I picked the 6×6 and 10×10 for my set to get the needed level of difficulty. The 6×6 should fall quickly but you’ll need to notice a few constraints to get anything written down with certainty for the 10×10 puzzle.


Tents Reconstruction: Enter some trees and tents into the grid. The outside content of each row or column shows the correct order of appearance for that row or column. Each tent is adjacently attached to a tree (one tent per tree) and no tents can touch each other, not even diagonally. 

Nov 2010, Budapest, Hungary

Flashback #2 – 4x4x4 Minesweepers

Another inclusion to the set was this 4x4x4 Minesweepers. I first encountered it in OAPC 7, and Serkan Yurekli cited it as an invention from Ali Aldas.


4x4x4 Minesweepers: Locate the positions of 16 mines that occupy empty squares. The numbered cells indicate how many mines surround that cell. No mines can appear in the same cell as another mine in another grid.

Nov 2010, Budapest, Hungary

Flashback #1 – Overlapping Sudoku

Every since I was hooked on puzzles from a children magazine when I wasn’t quite seven, I’ve been imitating most of my favourite puzzles in a drawing book. The usual victims of my poorly drawn puzzles back then are my older brothers and a few friends from school. Fast forward ten years and that once crayon-grabbing tot is now puzzling people worldwide.

Before I get Somewhere Over the Rainbow running properly, I’ll kill time by taking you back in time. Have fun with the puzzles I will be digging up for your enjoyment.

My first attempt at real puzzle-construction was thankfully rejected by Zoltan Horvath in 2009. Looking back at my produce, I had to laugh at my audacity to even submit that to him back then. The word “terrible” doesn’t even suffice. Better news came a year later though, I had round 11 of the 11th 24 Hours Puzzle Championship all to myself. Here’s one of my favourites:



Overlapping Sudoku: Fill in numbers 1-9 so that no numbers repeat in any row, column and outlined 3×3 boxes. Two grids are solved simultaneously.

Nov 2010, Budapest, Hungary