The Mathematics of Encryption

 asfdasfdasfd

Comments

Post a Comment

Popular posts from this blog

Ding!

The last time I used a typewriter was when I was a freshman in college.  I found an old typewriter in the library and used it to write letters to my cousin.  A fair amount of letters on the thing didn't work and I never remembered to send those letters - both fitting symbols for the place of the typewriter in modern society.  But, like that typewriter that probably still hangs out in a dingy corner of the library, the mechanico-social conventions surrounding typewriters also limp on: enter the bell alert. Try copy and pasting either of these bits of code into a new program file and running it in your console: ring-a-ding.rb puts `clear` puts "Press enter to ring the bell!" x = "" while x != "bye" x = gets . chomp puts " \a " end bellz.js let i = 0 while ( i < 5 ){ console . log ( ' \u0007 ' ) i ++ } Music! (...well, sound at least) The Ruby escape character "\a" and the Uni...
Read more

Making Logic Gates in JavaScript

Image
Everyone knows that computer programs are made of bits - the ones and zeros that hold all the information that keeps our modern life running. But how do you get from numbers to programs - how simple ones and zeros do  anything? The answer is logic gates (as well as a whole bunch of stuff about how electronics are built - you need to actually make these logic gates on out of circuits in order for our logic structures to be enacted; but I'm a programmer, not an electrical engineer, so let's not go there).  A logic gate is what's known as a  Boolean function , a mathematical operation that takes in bits and spits out more bits. Each logic gate takes in two bits of information (as mentioned before, generally denoted as a 1 (also sometimes represented as true ) or a zero (also sometimes represented as false )), so there are four possible inputs to a logic gate: {0, 0}, {0, 1}, {1, 0}, and {1, 1}.  For each of these inputs, a logic gate can spit out either a 1 or a 0, so t...
Read more

Big O Time

Image
Here's a great way to approximate the Big O time of your algorithm: just run it with differently sized inputs. That's right, that's all you have to do* (*there's more to it, we'll get to it in a sec).  You don't need to follow your inputs around, count any loops, look for best case and worse case scenarios.  You can get a pretty good approximation by following the steps below. 1.  Speed test your algorithm .  Make sure you have at least 3 inputs - if you're working with an array, make sure there's 3 elements, if you have a string make sure there's at least 3 letters, etc.  Larger inputs will make this test more accurate.  Note down how fast your algorithm was. 2. Double the number of inputs. 3. Speed test your algorithm again.  Got a number? Good. 4.  Now, divide the second speed test result by the first one. Once you've got that ratio, you're good to go!  Simply compare your ratio to the following chart: Ratio Big O time approximately 1 O(1)...
Read more