Project Euler

Project Euler is a website started by Colin Hughes as a result of a sub-section he previously maintained on mathschallenge.net. It provides a growing collection of mathematical/computing problems for project members to solve. Membership is not exclusive and can be gained by simply filling out the registration form and submitting it.

The following solutions, contributed by Tim Sneddon, are all written in PL/I. Although they were developed on OpenVMS they should compile with little or no change using other PL/I compilers. Look within the source module for build instructions (for OpenVMS at least).

Problems

Problem 1: Add all the natural numbers below one thousand that are multiples of 3 or 5.
Problem 2: Find the sum of all the even-valued terms in the Fibonacci sequence which do not exceed four million.
Problem 4: Find the largest palindrome made from the product of two 3-digit numbers.
Problem 5: What is the smallest number divisible by each of the numbers 1 to 20?
Problem 6: What is the difference between the sum of the squares and the square of the sums?
Problem 7:What is the 10001^st prime number?
Problem 8: Discover the largest product of five consecutive digits in the 1000-digit number.
Problem 9: Find the only Pythagorean triplet, {a, b, c}, for which a + b + c = 1000.
Problem 10: Calculate the sum of all the primes below two million (alternate solution).
Problem 12: What is the value of the first triangle number to have over five hundred divisors?
Problem 14: Find the longest sequence using a starting number under one million.
Problem 42: How many triangle words does this list of common English words contain?

Problems

Links