What's New - July, 2006
July 31, 2006: A new version of our Cutlist program, (V3.3), which implements "Human Intelligence" solutions was posted today. It allows users to drag and drop project part images onto supply part images if the program's "Artificial intelligence" solution is not satisfactory. HI solutions may be printed, saved and restored.
July 21, 2006: I took a break from working the next version of Cutlist (which lets the user to manually place parts to be cut on the supply pieces) to add a "write to file" button to our Big Combos program. A user wrote asking that I increase the maximum number of displayed combinations or permutations from 1,000 to 150,000. But that can't really be what he wants. With the text file, he can browse, print, import, or whatever, with the results.
July 17, 2006: Lots of fun this week exploring a new puzzle, Coal to Diamonds. The objective is to change 9 lumps of coal in a 3 x 3 grid through 2 intermediate phases and finally to diamonds as you click on them. And, of course, a clicked diamond changes back to coal. The catch is that each click changes not only that piece but the other pieces in that column and row. I think that this make it humanly impossible to solve the 9 coal to 9 diamonds case which takes at least 15 moves. I can solve 3 move cases easily, 4 move cases most of the time, and 5 move cases not at all. You can set up specific initial boards or random moves that can be solved in the number of moves you specify. The program solves cases using one of 3 "graph searching" techniques.
Just as interesting for me was exploring the game parameters. How many starting positions are there? Can they all lead to the 9 diamond board? Do any other positions require 15 moves to solve? Do any require more than 15? What is the distribution of games lengths? Download the program and find out.
July 6, 2006: Here's an email I received recently:
"Hi I have been searching the internet for a trick using square cards (or paper) with numbers and holes in them. The trick was to choose any number on the cards and one at a time turn each card to "yes" or "no" written on each card depending what cards have that number. after that the pile is to be turned over and the chosen number is shown through a hole on the bottom of pile. Do you know How I might search the internet for this?
Any help would be appreciated.
And here's one card of the Binary Card Trick solution I came up with:
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