Saturday, October 13, 2007

Hashi: innovative number-logic brainbreaker also known as Hashiwokakero


It's not every day that leading logic puzzle supplier Conceptis announces a new brainbreaker on their portfolio. This happened just this Friday as the company announced Hashi, its eleventh family of language independent logic puzzles. Hashi is an innovative bridge-connecting number-logic puzzle also known as Hashiwokakero (橋をかけろ Hashi o kakero; English: "build bridges!") and Bridges, invented by Nikoli Puzzles in Japan around 1990.



Starting October 12, four new Hashi puzzles are available every week in Conceptis' Free Weekly Puzzles section. Additional free Hashi including high-res solutions as the above very hard 20x26 model, are available from the official company catalog. Here are short instructions how to solve Hashi, taken from the Conceptis site:

"Each circle represents an island and the number in each island tells how many bridges are connected to it. The object is to connect between islands according to the number of bridges so that there are no more than two bridges in the same direction and there is a continuous path connecting all islands together. Bridges can only be vertical or horizontal and are not allowed to cross islands or other bridges."



According to Wikipedia, Hashi puzzles appeared in The Times and have also been published in English under the name Bridges or Chopsticks. In France, Denmark, the Netherlands, and Belgium Hashi puzzles are published under the name Ai-Ki-Ai. Hashi puzzles first appeared September 1990 in issue 31 of Puzzle Communication Nikoli in issue, although an earlier form of the puzzle appeared December 1989 in issue 28.

1 comment:

  1. I feel a strong connection to Hashis because they are almost like connected planar graphs (http://en.wikipedia.org/wiki/Planar_graph) in mathematics graph theory. The exception is that in the definition of graphs two vertices between nodes are usually not included. I made my Master's final paper about graph theory combined to coding theory :) BTW, graph theory is considered to originate from Euler's paper "Seven Bridges of Königsberg" in 1736.

    ReplyDelete

Note: Only a member of this blog may post a comment.