To my 7 loyal readers and the 200 people that viewed/hit my page last friday after I posted the PI math problem, I have your answer. Let me say that this is a pretty good way to solve the problem but I don't really agree with the problem definition of "alphabetic shift cipher" and the way the actual answer played out. On the other hand, I KNEW "mathmovesu" had to be part of the answer but I thought it was at the beginning. Oh well. I did love some of the comments the original post got -both relating to the math AND/OR the pudding! Quite randomly addictive!
Answer:
“The digits of p can be obtained from the internet. The most common digit can also be found by doing a search on Google. One way is to load the 100,000 digits into Word. Use the find and replace functions to take out any carriage returns or other non-digits. Then use the find and replace to change each digit to another character, like an “x”. The find and replace will tell you how many it removed. Doing this you can see that the digit “1” is the most common. I also used Word to find the longest monotonic continuous integer sequence. In Word, I used the find function to look for sequences of “12345” etc. Each time it found one I looked to see what the number preceding and following was to see if there was a longer sequence. It turns out that “12345” is the longest sequence in the first 100,000 digits. So that becomes the key for decrypting the message. There are 15 characters. The first is shifted backwards 1 letter in the alphabet, the second 2, the third 3, the fourth 4, the fifth 5 and then it repeats, the sixth 1 and so on. This turns JNRZJNCWLRPXHWZ into ILOVEMATHMOVESU which is the answer!”
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2 comments:
I thought it was a little odd that a "chief systems engineer" would use MS-Word (and not something more sophisticated, like a script) to count the frequency of the digits (especially when the data could be found on several webpages). Further, why would he search for each occurrence of "12345" and then look at the digits before and after it? It was stipulated it should start with 1, and if he wanted to see if there was a "12345" with a "6" after it, why not just search for "123456" (and, not finding it, conclude that "12345" was the longest sequence)? Anyway, sounds like about 100 people got it, and the prize went to someone on my campus (Aurora). Woot! :)
Paul
As a follow-up, you can get the digit frequency from: http://www.eveandersson.com/pi/precalculated-frequencies (the first result in a Google search)
Paul
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