Did you solve it? Are you a genius at gerrymandering? | Mathematics
Earlier in the day, I defined three logical puzzles Gerrymandering. Here they are again with solutions.
In each of the grids below, the challenge is to find the unique electoral card in which the minority color gains the most regions. A region is defined as a contiguous block of cells which are attached horizontally or vertically. (A region cannot contain any cell that is not connected diagonally, that is to say via a corner.) Winning a region means having the most cells in this region.
To solve using pencil and paper, click here for printing (and some bonus puzzles). To play on your screen, below each puzzle is a link to an interactive version.
The puzzles were designed by Brady Forrest (aka deckard). He talks about mathematics behind the puzzle (and shows how to solve them) in this YouTube clip:
All solutions below.
Puzzle 1: Easy
Divide the grid into 5 regions of 5 cells each. Violet, the minority color, must win the majority of regions.
Puzzle 2: Medium
Divide the grid into 5 regions of 10 cells each. Violet, the minority color, must win the majority of regions. No link authorized in any region.
Puzzle 3: Hard
Divide the grid into 7 regions of 7 cells each. Blue, minority color, must win the majority of regions. No link authorized for first place in any region.
Solutions
Thanks to Deckard for sharing his puzzles. Thanks to Starwort for the interactive versions.
I have been putting a puzzle here on alternative Mondays since 2015. I am still looking for big puzzles. If you want to suggest one, send me an email.
In other news related to Gerry, here is a fact of my new book, Football School Facts. Gerry Taggart (ex-Bolton) is one of the four players in the Premier League to have been sent for their birthdays. The bad type of card! This Curio and hundreds of others appear in the book, the last of the long -term series that I write with Ben Lyttleton for children from 7 to 107 years old. The facts of the football school are in color, the Redback would make an excellent gift and are available at the Guardian bookstore.
