This was a neat question could be brute forced easily but that would be very slow. There is a table method which exploits the properties of prime numbers to find least common multiple of a set of numbers. The exact method can be found on the least common multiple wikipedia page
]]>A palindrome is a string which reads the same forwards and backwards for example 98789. The isPalinedrome(x) method checks if x is a palindrome by checking if x equals x in reverse. The n[::-1] call returns the reverse of n. The stride notation lets you filter in a interval of elements in a list. For example the call n[::2] for n = [1,2,3,4] would return [2,4]. Then a nested for loop is used to find the biggest palindrome made of the product 3 digit integers.
]]>This problem is a little tricky the solution looks simple but there are a few key things that let it run quickly. First we take the square root of 600851475143 and start searching from that value to zero. We can look in this range because any factor greater than the square root would have a multiple below it and thus not be prime. The second thing to note is the if statement which checks if we have found a solution. We check if it is factor before checking if it is prime. This cuts down on the number of expensive prime checks because they are only done after confirming that a value is a factor of 600851475143. This is because the 'and' statement returns false after the first operand is checked and doesn't waste time computing the second one (the prime test)
]]>Problem 2 of project euler is another simple one. The next value in the fibonacci sequence is the sum of the previous 2 values. As we produce the next value in the fibonacci sequnece we sum up the even values.
]]>First problem starts off pretty simple. For each of the numbers 1 through 1000 we check if they are divisable by 3 or 5 and sum up the values that are. Checking if a interger is divisable is done using the modulo operator % which returns the remainder of a division. If the remainder is 0 then the two operands divide evenly.
]]>During my undergrad I spent a lot of time programming in Java, C and C++. I also played with Scheme and Prolog for a semester or 2. I've decided to branch out and learn Python a lanaguage whos passionate fanbase has lead me to believe it is made from unicorn farts and fairy dust. It seems like a very versitile language with a nice crisp syntax. I'm also looking to learn web development skills which makes Python a nice fit.
Since I have programming experience under my belt I've chosen Dive Into Python as my primary resource. I'm about 50 pages in and so far seems like the right book for me. It has a good pace and assumes readers have prior programming experience. I also looked into Learn Python the Hard Way which looks like a fantastic way for a beginer to get into programming and learn Python. Both these resources are free to view online.
The IDE I've gone with is Aptana Studio which is based off of Eclipse my favourite Java programming enviroment. It's geared towards web development and has the PyDev python plugin for eclipse built in. Worth checking out.
I'll be completing Project Euler problems using Python and posting my solutions here as I go. Not aiming for the 100% most efficient solutions just trying to learn the Python syntax and its in and outs.
Lastly I've finally gotten around to adding SyntaxHighlighter to this blog so I can post nicely formated code snippits. Example with a little prime number generator I wrote earlier today below.
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