According to the Project Euler website, “Project Euler is a series of challenging mathematical/computer programming problems…”
Always a fan of puzzles, I have decided to share my attempts and solutions here.
Note: If you are trying to solve Problem #1 for yourself, DO NOT READ AHEAD!
Problem #1
Problem Description
Problem #1 entails finding the sum of all of the multiples of 3 or 5 under 1000.
Solution
This one was rather simple. The modulo mathematical operator (%) finds the remainder of one number divided by another. If the remainder is 0 (i.e. if x % y = 0), then x is a multiple of y.
Therefore, the task is simple: count from 1 to 999 (we want the numbers below 100, remember), check if n % 3 = 0 or n % 5 = 0. If either is a match, we add that to the running total.
Code (PHP)
Total Sum: 233168