Questions tagged [project-euler]

Use this tag for questions that came from the Project Euler website.

27 questions
60 views

Integer linear programming can't find global minimum

I was working with Project Euler Problem 418 using Mathematica and got in trouble. I wrote a function to find the unique factorization triple which minimizes c / a for integer n. ...
181 views

Generation of Step Numbers

I am working on Project Euler 178 but got stuck in trying to optimize my code. The following text comes from the problem: Consider the number $45656$. It can be seen that each pair of ...
155 views

How to loop through a large number in mathematica

I am trying to find all divisors of 200! [Project Euler, problem 608 - in case anybody is curious]. It has many divisors and hence using ...
61 views

Converting sequece of code into a function [closed]

I constructed a pretty basic sieve of Eratosthenes and would like to use it as a function rather than copy pasting output, how do I achieve ...
273 views

How to simulate a Disk operation in a good way?

I want to simulate an operation on a disk, originally specified in project-euler problem #566. Here is a description of the problem. I want to simulate a disk with arbitrary partitions, but only two ...
165 views

How to implement this simple procedural style algorithm efficiently in Mathematica style code?

I am trying to move my C solution code for project euler problem 135 to Mathematica. But I encountered serious performance problem. The algorithm is very simple, here is a plain translation: ...
470 views

Euler Project Problem 18

I use Mathematica to implement a function, which output the position path in the triangle required. And the elements are found to be {75, 95, 47, 87, 82, 75, 73, 28, 83, 47, 43, 73, 91, 67, 98}, which ...
199 views

Counting runs in bits, along with their starts and lengths, in functional style

Here is some code to visualize Project Euler Problem 502. The code scans for runs of bits in the binary representation of an integer, and outputs the beginning position of each run and the length of ...
80 views

Why does this function recur forever? [closed]

I am trying to solve Project Euler Problem 31, but I don't want answers for that. I just want to know why this function recurs forever. It just keeps subtracting one forever, on the ones where it goes ...
274 views

How to Optimize Solution? (Project Euler #14) [duplicate]

Link to Question: https://projecteuler.net/problem=14 I began by defining the following functions below. ...
571 views

Copy/Pasting a Grid of Numbers from Project Euler

On Project Euler Problem 11 (link: https://projecteuler.net/problem=11), there is a 20x20 grid of numbers. However, when I pasted it into Mathematica, I got this strange result where the times symbol '...
189 views

Integer partitions and dice result probabilities

This is a Project Euler question, so no spoilers :] I was going to try to solve it by first finding how many ways a certain sum can be acquired from a number of dice using ...
289 views

The usage of MapIndexed, can it be removed?

project euler 67 When I'm solving this problem, my solution is as following. You can download the data file there. ...
693 views

Code efficiency improvement needed solving problem 499 in Project Euler

I am trying to solve https://projecteuler.net/problem=499 by constructing a transition matrix and finding its steady state. Here is my code: ...
194 views

How to speed up my code about Divisors?

This code is about PE496 In:= ParallelSum[n*Count[Divisors[n^2], a_ /; n < a < 2 n], {n, 1, 10^5}] // AbsoluteTiming Out= {5.987342,10724527832} I ...
1k views

Collatz optimization

I'm VERY new to Mathematica programming (and by new I mean two days), and was solving Project Euler question 12, which states: Which starting number, under one million, produces the longest [...
2k views

How to speed up my Project Euler code

The evaluation speed of Mathematica often depresses me. It did it again when I wrote a code to solve a Project Euler problem. https://projecteuler.net/problem=206 Here's my code: ...
387 views

Performance of compiled functions (Project Euler No14)

I was playing around with the project euler problem 14. The solution I came up with is listed below as cf1. The solution works fine but I get the compiler warning: ...
635 views

Why is my solution to PE #5 so slow

I'm new to Mathematica and it was suggested to me to go through the Project Euler problems in order to learn it. However, I can't quite figure out why my solution to #5 is so slow. The problem: ...
31k views

Even Fibonacci numbers

Today, I found the Euler Project. Problem #2 is Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: ...
564 views

Improve the performance of solutions to Project Euler (#14)

Problem I have following code, when n<=10^5 it's not slow, but n>2*10^5 it's became very slow. I think maybe some temp value greater than 2^31-1, so make compile invalid. Could you give any idea ...
342 views

Project Euler (memory and speed issues)

Let n be a positive integer. An integer triple (a, b, c) is called a factorisation triple of n if: 1 ≤ a ≤ b ≤ c a·b·c = n. Define f(n) to be a + b + c for the factorisation triple (a, b, c) of n ...
141 views

Strange function definition result [duplicate]

I'm relatively new to Mathematica, and I'm trying to define a function f(k) that would do the following: For any positive integer $k$, a finite sequence $a_i$ of fractions $\frac{x_i}{y_i}$ is ...
389 views

How can this DivisorSigma code be made fast?

Since Project Euler problems are now fair game for questions I have a question of my own. A certain problem* states: For a positive integer n, let σ2(n) be the sum of the squares of its divisors. ...
548 views

Improve performance and style of solution to Project Euler #32

Since I'm fairly new to Mathematica, I'm trying to learn better ways to improve my coding skills so I've turned to Project Euler and this site to speed up my learning pace. Anyways, I was trying to ...