28, 2002: I've spent most of this past week adding an explanation
facility to my "Logic Puzzle Solver" program. It
solves most of those logic puzzles found in Logic Puzzle
magazines from Dell Publications. It will take another week or
so of polishing, and we have the back-east grandkids visiting next
week, so I decided to post this beginner's level T-Shirt program to fill
the gap. T-Shirt #5 helps us find
the smallest 3 (or 4, 5, 6, 7, 8 or 9)-digit emirp for the
front of our shirt.
July 23, 2002: Today, I added a long
"site search" feature to the left border of each page
over in the Programs
section. With more than 100 programs now (Google has
indexed 300 pages), I'm having trouble locating things, and I put
them there! Send me feedback if you have any problems.
22, 2002: Some kids wanted to set up a lemonade stand to make
money. To set themselves apart from the other lemonade stands on the block, they decided to sell their lemonade by the pound. They found an old balance beam scale, the kind with a weight pan on each side, and three weights. They discovered that they could sell any whole number of pounds from 1 to 13. What weights did they have.?
Weights #1 searches for the answer to
this question for any number of weights from 1 to 5. There's also a
scale where you can practice with things of unknown weight, I guess
they could be lemonade containers.
15, 2002: Here's a small puzzle that I've named Solitaire
for Squares. No chance involved here, just a little thought
and perseverance. Remove the Spades and Hearts from a deck on
cards. Layout the 13 Spades in order Ace through King. Place a
Heart on each Spade so that the sum of each Spade-Heart pair is a perfect
square (4, 9,16, or 25). Just to prove that it knows how, the
program will provide hints if you really get stuck.
13, 2002: A Magic Cube is a logical extension of a magic square
into the third dimension. Here's a
Magic Cube program that doesn't haven't have much user
interaction, but it does search, (and find), all 192 semi-perfect
magic cubes of order 3. They are not quite perfect because the
diagonals on each face cannot be made to sum to the required magic
constant, 42. But the 31 rows, columns, pillars, and space
diagonals (corner to opposite corner through the center number) all
can. By the way, the smallest cube that can be perfect is
8x8x8. Beware! For a small percentage of the population,
playing with magic squares, cubes, and hyper-cubes may be