Author Archives: Multimedia Mike

Graph Traversal Puzzle

Pickover came through with a slightly more involved brute force challenge. As usual I’ll spare you the flowery setup (though I did find it curious that it involved a character named Ben trying to reach one named Jennifer) and distill the essential details. Given this graph of values:

 1  2  3  4  5
 6  7  8  9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25

find a path from any square in column 1 to any square in column 5, moving up, down, left, or right, such that the sum of all squares traversed tallies 90.

I liked writing this program because it is the most algorithmically interesting thing I have done in a long time, even though I originally solved the wrong problem. The way I originally read the problem, the task was to move from node 1 -> node 5, traversing up, down, left, or right, and find a path where the values sum to 90.

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Send More Geese

Pickover’s puzzle for the weekend of February 4-5 challenged the reader to find 8 numbers to stand in for the letters D, E, G, M, N, O, R, and S such that the equation SEND + MORE = GEESE would be true. Again, there are multiple solutions. I’m pleased to report that I found 3 orders of magnitude more solutions than the big brain himself.

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Another Pickover Puzzle

Cliff Pickover’s puzzle from 2006-02-22 queries the reader to come up with 3 pairs, or possibly more, of numbers, m and n, which satisfy the equation n! + 1 = m2. I didn’t think too hard about it. I just went straight to code which turned out to be a good thing because one of the solutions is quite large. Click more to see the reasoning I went through and the solutions output from my program.

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SDL Corruption Corrected

When I do presentations on multimedia technology I make the point that data is more important than code which is to say that understanding data formats is more useful than being able to run binary code. This little exercise is a good illustration of that. Initially, if someone wanted to see the multimedia, they needed access to an original IBM PC to run it as it was originally intended. It is also apparently possible to run it under DOSBox. In that case you are still running the original binary code to interpret the data. Now along comes this third solution which throws out the original code and just interprets the data with portable, open code.

Download Trixter’s original 8088 Corruption package from his site. Download the sdl_corruption.c program and the CGA_FONT.8X8 font file from http://multimedia.cx/sdl-corruption/. Make sure you have SDL. Compilation is straightforward on Unix. At the very least, it works on x86 and AMD64 machines running Linux. You are on your own for other platforms.


Corrected Eiffel Breakdancer Image
There, that looks correct, or as correct as it is supposed to look.

I did not bother to add sound output because I was lazy. Hey, I solved the harder problem of rendering the font vectors. I also added a few spiffy features such as allowing the user to seek and pause the video.