Tagged Questions
1
vote
4answers
1k views
Sieve of Eratosthenes: making it quicker
I was thinking about doing problem 23 of Project Euler. It includes the difficulty where you have to factorize primes. I had already done that in problems I solved earlier, but it was only necessary ...
27
votes
7answers
4k views
Project Euler problem 1 in python
I'd like suggestions for optimizing this brute force solution to problem 1. The algorithm currently checks every integer between 3 and 1000. I'd like to cut as many unnecessary calls to ...
5
votes
4answers
624 views
Any better way to solve Project Euler Problem #5?
Here's my attempt at Project Euler Problem #5, which is looking quite clumsy when seen the first time. Is there any better way to solve this? Or any built-in library that already does some part of the ...
4
votes
1answer
712 views
Project Euler Problem 12 - Highly Divisible Triangular Number - Python Solution Optimization
Project Euler Problem 12 asks (paraphrased):
Considering triangular numbers Tn = 1 + 2 + 3 + … + n, what is the first Tn with over 500 divisors? (For example, T7 = 28 has six divisors: 1, 2, 4, ...
4
votes
2answers
412 views
Project Euler problem 92 - square digit chains
Link to problem.
A number chain is created by continuously adding the square of the
digits in a number to form a new number until it has been seen before.
For example,
44 -> 32 -> 13 ...
17
votes
5answers
852 views
Count distinct primes, discarding palindromes, in under 2 seconds
Problem Statement
Generate as many distinct primes P such that reverse (P) is also prime
and is not equal to P.
Output:
Print per line one integer( ≤ 1015 ). Don't print more than
...
6
votes
4answers
727 views
Finding the Pythagorean triplet that sums to 1000
Project Euler problem 9 says:
A Pythagorean triplet is a set of three natural numbers, a < b < c,
for which,
a2 + b2 = c2
For example, 32 + 42 = 9 + 16 = 25 = 52.
There ...
4
votes
2answers
284 views
Improving runtime of prime generation
I just answered the question on project euler about finding circular primes below 1 million using python. My solution is below. I was able to reduce the running time of the solution from 9 seconds to ...
