Questions tagged [collatz-sequence]
This tag should be used for code related to the sequences described in the Collatz conjecture.
74
questions
10
votes
4
answers
3k
views
3n + 1 programming challenge in Python
I am trying to find a efficient solution for the 3n + 1 problem on uvaonlinejudge. The code I have uses memoization using a dictionary. I am getting a 'Time limit Exceeded' error when I submit the ...
- 19
10
votes
2
answers
2k
views
Collatz sequence in C
First of all, if you're unfamiliar with the Collatz sequence, it recursively applies the following function to an integer:
$$ f(n) = \begin{cases} n/2 & \text{if } n \equiv 0 \pmod{2}, \\ 3n+1 &...
- 31.5k
2
votes
3
answers
921
views
Automate the boring stuff with python - The Collatz Sequence
The Collatz Sequence
Write a function named collatz() that has one parameter named number.
If ...
- 3,076
6
votes
3
answers
2k
views
Optimize Collatz conjecture
This was the exercise:
Exercise PSD
Think about a number under 25. Write down the number. If the number is
even, divide in to two en write down the result below. If the number
isn’t even (...
- 15
1
vote
1
answer
74
views
Meta Collatz Sequence
Context
Chapter 6 of Learn You A Haskell contains a function called chain, which outputs the Collatz sequence of a given input.
(In short, it takes a natural number....
- 616
7
votes
3
answers
26k
views
Hailstone Sequences in Python
For the problem given:
Douglas Hofstadter’s Pulitzer-prize-winning book, Gödel, Escher, Bach, poses the following mathematical puzzle.
Pick a positive integer \$n\$ as the start.
If \$n\$ is ...
CommunityBot
- 1
5
votes
0
answers
172
views
A Python 3 script that generates art using matplotlib
I am always super interested in both science and art, science and art are two different ways to describe the objective reality, they are two sides of the same coin, in many areas they overlap, and ...
- 144k
3
votes
1
answer
221
views
Collatz conjecture with plots
I have an assignment where I write a Collatz Conjecture program for a series of starting values from 1 to N and make two plots: number of iterations vs starting value and computed numbers vs starting ...
CommunityBot
- 1
3
votes
2
answers
150
views
Beating the compiler with a simple program finding the longest collatz sequence
I found this question in Stackoverflow asking why his/her assembly program isn't faster than the C++ program. In his/her assembly program I saw the lines ...
- 27.6k
10
votes
4
answers
5k
views
Python Automate the Boring Stuff Collatz exercise
I'm looking for some feedback on my code for the collatz function exercise in the Python book Automate the Boring Stuff. It works, but doesn't feel very elegant to me. Is there a better way to ...
- 1
2
votes
0
answers
211
views
Maximizing Efficiency of Collatz Conjecture Program Python
My question is very simple.
I wrote this program for pure entertainment. It takes a numerical input and finds the length of every Collatz Sequence up to and including that number.
I want to make it ...
- 41
2
votes
1
answer
830
views
How to make my Collatz Conjecture code run a lot faster? (and even better, how do I implement it into multiple computers?) Python
I have been writing this piece of code for a while now, and I was wondering, is it possible to run this code multiple times on my pc? For example could I make the code solve all the numbers from 1 to ...
- 128
9
votes
3
answers
9k
views
Python - The Collatz Sequence
Can I get a review of my code for the the Collatz Sequence from Chapter three of Automate the Boring Stuff with Python?
The Collatz Sequence
Write a function named collatz() that has one ...
- 1
10
votes
2
answers
3k
views
5
votes
2
answers
220
views
Project Euler Problem #277
I am trying to solve Euler project problem 277 using python 3.8. First, I will show my program and than ask specific questions for enhancements.
The problem is a modified version of Collatz sequence. ...
- 75k
6
votes
2
answers
606
views
Basic Collatz program with input validation in Python
In chapter 3 of Automate the Boring Stuff with Python by Al Sweigart, one exercise asks to write a program which performs the Collatz sequence.
I wrote a basic version first, then added and ...
- 1,336
5
votes
1
answer
118
views
Collatz Conjecture Disprover Unit - Googol Edition
The Wikipedia article about the Collatz Conjecture has these quotes:
If the conjecture is false, it can only be because there is some starting number which gives rise to a sequence that does not ...
- 1,453
4
votes
3
answers
2k
views
Generator for the collatz conjecture sequence
I tried to write this code as concisely as possible. Is this the best way to do it?
...
- 3
5
votes
1
answer
108
views
Hailstone Sequence in NASM
For practice, I wrote some NASM code that prints out the hailstone sequence of a (unfortunately, hardcoded) number.
This is by far the most complex code I've ever written in NASM. I'd like advice on ...
- 9,474
2
votes
1
answer
211
views
Collatz sequence using Python 3.x
I created this program originally for Project Euler 14.
Here's the code:
...
- 33.5k
4
votes
3
answers
597
views
Calculating a Collatz Sequence
I've written a small script to calculate Collatz sequences. For background, read here about the Collatz conjecture. Largest number I've tried so far in my implementation is 93571393692802302 (which ...
- 266
4
votes
1
answer
530
views
Computational verification of Collatz conjecture using OpenCL
This code review request follows my previous request Computational verification of Collatz conjecture.
Unlike the previous program (which was designed for the CPU), this code should run on modern GPUs....
- 34.8k
4
votes
4
answers
383
views
Optimized Longest Collatz Sequence
I'm writing a program to calculate the longest collatz sequence for positive integers below some N. I have optimized it as far as I can - is there anything more I could do to optimize it? Any ...
CommunityBot
- 1
3
votes
2
answers
127
views
Computational verification of Collatz conjecture using gmplib
Prerequisites
The unsigned long type has a size of 64 bits.
The following macros are defined.
...
3
votes
1
answer
405
views
Computational verification of Collatz conjecture
Prerequisites
The typedef name uint128_t designates an unsigned integer type with width exactly 128 bits.
The ...
- 309
2
votes
1
answer
269
views
Automate the Boring Stuff - Collatz Exercise
I wrote the following code for the Collatz exercise: The Collatz Sequence
Any feedback is appreciated.
Write a function named collatz() that has one parameter ...
Mast♦
- 13.4k
1
vote
1
answer
120
views
python : Collatz Sequence
I am a beginner in python. I found this problem in the book Automate the Boring Stuff with Python. How can I improve this program using latest version of python.
...
- 43.3k
-4
votes
3
answers
5k
views
Finding the longest Collatz Sequence
Inspired by Project Euler 14:
Longest Collatz Sequence
"Which starting number, under one million, produces the longest Collatz Sequence chain?"
I wrote the following Java code:
...
- 1
0
votes
1
answer
306
views
Finding the longest Collatz sequence using Go, concurrently
I am working through this problem on project euler.
Basic purpose of the code:
...
- 3,466
2
votes
3
answers
2k
views
Determine Collatz sequence length for given starting values
I am trying to get into the habit of solving programming puzzles in my spare time but am stuck on the first one (which I know can be for a large number of reasons, hence my posting for help). Shown ...
CommunityBot
- 1
3
votes
4
answers
1k
views
Testing a Collatz Conjecture Conjecture (Python)
I had an intuition that the maximal trajectory lengths for collatz conjecture numbers would be produced by numbers of the form (2**n)-1 so I wrote a program to test ...
CommunityBot
- 1
3
votes
2
answers
547
views
Contest Solution: Hailstones
The Problem
In the January 1984 issue of Scientific American, an interesting sequence of numbers known as a hailstone series was described. The series is formed by generating the next number ...
- 144k
15
votes
2
answers
3k
views
Automate the Boring Stuff with Python - The Collatz sequence project
I am new to programming and started learning with Automate the Boring Stuff with Python. I just completed chapter 3's "Collatz sequence" project.
I was wondering what would you do differently and ...
- 33.5k
1
vote
1
answer
212
views
Longest Collatz sequence in Scala
I am trying to find the longest Collatz Sequence:
Which starting number, ≤ N, produces the longest chain? If many possible such numbers are there print the maximum one. (1 ≤ N ≤ 5×106)
I tried ...
- 144k
4
votes
0
answers
287
views
Collatz fractal in Rust
Among the many fractals, there is Collatz Fractal based on a complex extension of:
$$f(x) = \left\{
\begin{array}{ll}
\frac{x}{2} \space \text{if even} \\
3x + 1 \space \text{if odd}
\end{array}
\...
- 144k
1
vote
3
answers
663
views
Euler Project 14 Longest Collatz Sequence [closed]
I have been working through the euler project and I have created the following code for Problem 14, which asks which starting number, under 1 million, produces the longest Collatz Sequence chain.
It ...
- 156
3
votes
2
answers
1k
views
Calculating the Collatz conjecture of a number
I've made a Collatz Conjecture sequence calculator and I would like some feedback on what I can do better in regards to the code I've implemented, i.e. bad practices you see, improvements that can be ...
- 3,414
5
votes
2
answers
194
views
Euler Project 14 (Longest Collatz Sequence)
Project Euler 14 asks: Which starting number, under one million, produces the longest Collatz sequence?
I've been trying to optimize this solution to execute in less then 1s. Agenda for first 50 ...
- 3,597
4
votes
1
answer
192
views
Generating the Collatz sequence in F#
Below is my code for building the collatz sequence so a given number. I'm trying to make the function tail recursive and I believe that this impelemtation is tail recursive but I'm not yet so ...
- 507
3
votes
1
answer
152
views
Project Euler problem #14 (longest Collatz chain) in Swift
This is my Swift code for finding the starting number, under one million, which produces the longest collatz chain.
...
- 23.2k
5
votes
4
answers
8k
views
Collatz Conjecture (c++)
I am new to C++ and this is my first program. The objective of this program is to fully complete the sequence called the Collatz conjecture.
It concerns a sequence defined as follows: start with ...
- 171
4
votes
2
answers
1k
views
Memoized Collatz sequence
Here is one of my programs that utilized memoization and array to improve performance and memory usage. The performance seems satisfactory but the memory usage is ridiculous and I can't figure out ...
CommunityBot
- 1
3
votes
1
answer
370
views
Collatz Conjecture Meet of 2 Numbers
I need the most efficient way to calculate when the Collatz Conjecture of two numbers, a and b respectively, are the same. Here ...
- 28.5k
3
votes
2
answers
538
views
Counting terms in Collatz sequences until 1 is reached or a limit is exceeded
My friend and I are into competitive programming and we wrote two very similar programs for a problem. His got accepted with a runtime of 0.6 s while mine didn't get accepted even after 3 s.
I was ...
- 28.5k
3
votes
3
answers
766
views
Longest Collatz sequence using dynamic programming in Java
I'm not getting where else should I optimize it. Is there any way to optimize this code any further? Just give me hints.
...
- 4,287
4
votes
2
answers
7k
views
Project Euler #14 - Longest Collatz Sequence in Python
I recently solved Project Euler Problem 14 in Python:
The following iterative sequence is defined for the set of positive
integers:
...
- 1,884
3
votes
2
answers
295
views
UVA 100: “The 3n + 1 problem” take 2
This is my second attempt to solve this problem, my first attempt is here: UVA 100: "The 3n + 1 problem"
This time I tried to take lessons from the failures and mistakes You pointed out in ...
CommunityBot
- 1
12
votes
2
answers
2k
views
"Longest Collatz sequence" in C slower than in Python 3
This tight-looped memoization-less C solution to Project Euler's problem 14 seems efficient, but ran much slower than a similarly trivial Python 3 program. For the desired ...
- 34.8k
8
votes
4
answers
1k
views
Project Euler problem 14 (longest Collatz sequence) in Swift 3
I was trying to solve Project Euler:Problem 14 using Swift 3, but it takes ages to give me an answer, which is a sign that my code is absolute garbage performance-wise. What could I do to increase the ...
CommunityBot
- 1
6
votes
2
answers
814
views
UVA 100: "The 3n + 1 problem"
I’ve solved UVA Problem 100: The 3n + 1 problem . In short, the task was to write a program that calculates a maximum of Collatz sequence lengths for any given range of starting values.
My program:
<...
CommunityBot
- 1