Advent of Code: 2015 – Day 01
Part A Problem: Starting at zero, move up one floor for every '(' and down one floor for every ')'. Solution: Read in the input one character at a time…
Changing the timezone in Debian Buster
I recently spun up a couple of virtual servers with the Mythic Beasts provisioner, which didn't give me the option of selecting my timezone. As a result the servers were…
osTicket and Vagrant
osTicket is a self-hosted and open source ticketing system written in PHP. I wanted to give it a try as one option for a client's support needs, but with a…
Project Euler: Problem 8
Problem: Find the largest product of any 13 adjacent digits in a 1000 digit number. Solution: Move through the 1000 digit number with a sliding window of 13 digits. For…
Pretty print XML in PHP
As part of my freelance work I send data to APIs, often using XML for data transfer. I log the XML sent and received for debugging and auditing, however the…
Project Euler: Problem 7
Problem: What is the 10,001st prime number? Q. How do we find the nth prime number?A. Build a Sieve of Eratosthenes large enough to contain the nth prime number. Q.…
Project Euler: Problem 6
Problem: Find the difference between the sum of the square of the first 100 natural numbers, and the square of the sum of the first 100 natural numbers. Solution: PHP…
Project Euler: Problem 5
Problem: Find the smallest number with all the integers 1 to 20 as factors (i.e. divisible without a remainder). Q. What is the simplest way to find the lowest number…
Project Euler: Problem 4
Problem: Find the longest palindrome made from the product of two three-digit numbers. Q: How do we work out if a number is a palindrome?A: Convert it to a string…
Project Euler: Problem 3
Problem: What is the highest prime factor of n? In this case: n = 600851475143 Q: What is the simplest way to find the highest prime factor of n?A: Try dividing…