Questions tagged [mathematics]
For code that aims to solve problems in all branches of mathematics. (Please do NOT use this tag for incidental trivial use of arithmetic. A simple test to apply is: would an amateur or professional mathematician take an interest in the question?)
66
questions
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7
answers
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Quadratic expression calculator
I'm hoping to get some feedback on how to improve and optimise a program I wrote which takes three values as input (via the terminal) and uses them in the quadratic formula.
I'm aware this is mostly ...
user40096
5
votes
4
answers
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Project Euler #5 - Lowest common multiple of 1 through 20
This is my code. All comments welcome. Last time run it only took 335 milliseconds:
...
user34073
148
votes
17
answers
19k
views
Disproving Euler proposition by brute force in C
I wrote a little bit of code to brute force disprove the Euler proposition that states:
$$a^4 + b^4 + c^4 = d^4$$
has no solution when \$a\$, \$b\$, \$c\$, \$d\$ are positive integers.
I'm no ...
- 2,343
16
votes
1
answer
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views
Large Number Limit Extravaganza
I am writing a program that computes
$$n-n \cdot \left(\prod_{i=1}^n (1-\frac{1}{p_i})\right)$$
which is rewritten in my code as:
$$\left(1-\left(\prod_{i=1}^n(1-\frac{1}{p_i})\right)\right) \cdot ...
- 327
12
votes
4
answers
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Type system for different representations of angle value
I want to implement a Type system for different representations of an angle value. Motivation to implement this as a type system comes from this question.
Angle can be represented using the ...
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10
votes
2
answers
21k
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5
votes
4
answers
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C++ determinant calculator - follow-up
After following some suggestions you can find here, I'd like to show you the result:
...
user214772
4
votes
1
answer
330
views
Mendelian inheritance
I started out with the Rosalind problems a while back. Turns out it's a great way to learn a new language. I'm still trying to learn Ruby, and while I haven't managed to use regular expressions as ...
Mast♦
- 13k
3
votes
2
answers
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BigRational based on BigIntegers
For Project Euler I've implemented a BigRational. The functionality is rather limited, just things I needed or will probably need soon. The style departs a bit from ...
- 13.5k
3
votes
1
answer
375
views
Computational verification of Collatz conjecture
Prerequisites
The typedef name uint128_t designates an unsigned integer type with width exactly 128 bits.
The ...
- 289
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votes
9
answers
7k
views
Solving the Lazy Hobo Riddle
I would like help in optimizing this calculation, which is from the Lazy Hobo Riddle:
There once were 4 hoboes travelling across the country. During their
journey, they ran short on funds, so ...
user54410
34
votes
8
answers
11k
views
Checking if a number is divisible by 9
I tried to develop a new way to check if a number is divisible by 9. I have written my code and it is working fine. I'm not allowed to use *,...
- 451
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votes
4
answers
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Generalized Project Euler 1: A sledgehammer to crack a nut
The problem
Project Euler 1 is one of the most asked questions on site. However I wanted to solve the more general problem of division.
Multiples of a list
If we list all the natural numbers ...
- 5,675
17
votes
7
answers
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Euclid's Algorithm (Greatest Common Divisor)
According to Donald Knuth in "The Art Of Computer Programming", the following is how to find the greatest common divisor of two positive numbers, m and n, using Euclid's Algorithm.
Divide m by n ...
- 547
15
votes
4
answers
3k
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Calculator in C++
I made a calculator in C++. I wanted to ask is this code well written, understandable, and alright.
...
- 69
15
votes
3
answers
2k
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Wow that's a big integer! What's its largest prime factor?
I see that there are a few other people who have tackled Project Euler Problem #3. I hope you're not all sick of that question yet. I've not taken a look at those yet (purposely), but am about to now. ...
- 30.8k
15
votes
5
answers
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Sine function in C / C++
Due to software constraints, I cannot use the standard libraries, cmath, algorithm, templates, inline, or boost. I am also using ...
- 481
12
votes
6
answers
2k
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Beehive numbers - using goto in C++
I understand that using goto in C++ code is strictly unadvised, but sometimes, it really reduces the number of lines of code like in the following case.
This is my ...
- 329
10
votes
2
answers
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Project Euler Problem 530: sum of sum of greatest common divisors
Here is a description of Project Euler problem 530:
Every divisor \$d\$ of a number \$n\$ has a complementary divisor \$n/d\$.
Let \$f(n)\$ be the sum of the greatest common divisor of \$d\$ ...
- 251
10
votes
2
answers
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Fibonacci generator with Golang
This is my Fibonacci generator:
package main
import "fmt"
func main() {
for i, j := 0, 1; j < 100; i, j = i+j,i {
fmt.Println(i)
}
}
It's ...
- 203
9
votes
6
answers
3k
views
Decide whether a triangle is isosceles or not
I think I have pretty much the best code you can get when it comes to this particular task, but I'm always open to improvement. This code will check everything I can think of to make sure that it will ...
- 419
8
votes
0
answers
3k
views
constexpr Sin Function C++ 14
I have written a constexpr sin function using c++14 and would like to know what I can do to improve it. I am trying to balance code clarity/maintainability with ...
- 407
8
votes
1
answer
2k
views
Faster(?) factorial calculations
I saw this question, but was unable to answer because of my inexistant knowledge of Rust, so I decided to try and write an algorithm on my own and put it for review.
There is the casual way to ...
- 12.3k
8
votes
4
answers
7k
views
Pi-calculating program
I saw this question and answer about calculating pi on Stack Overflow, and I decided to write my own program for calculating pi. I used Python and only integers (I didn't want to use floating point ...
- 181
7
votes
2
answers
1k
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Simplified Bin Packing using JavaScript
This code determines the maximum number of boxes (one size) that can fit into the back of a truck, checking all possible orientations to ensure maximum Bin Packing excitement. This is (hopefully) the ...
- 393
7
votes
2
answers
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Helper function to solve Project Euler question 26
Project Euler problem 26 asks us to:
Find the value of d < 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part.
I wrote this function in Python to find the ...
- 295
7
votes
1
answer
3k
views
How do I optimize this Java cube root function for BigInteger?
I find that this function is one of the biggest causes of slow program execution. I can write a square root version with BigInteger only, but with the cube root, the algorithm sometimes gets caught in ...
- 307
7
votes
4
answers
815
views
Are there any bugs or ways to make my divisor code better?
After coding my divisor code which I did as a practice for my GCSE stuff which I have to take soon, I have decided to ask the community if there are any bugs or ways I can improve my code.
...
- 383
7
votes
1
answer
118
views
Weighted phase Laplacian formula
We have the following equation (weighted phase Laplacian):
\$c_{i,j} = U(i,j)\Delta^{^x}_{i,j} - U(i-l, j)\Delta^{x}_{i-1,j} + V(i,j)\Delta^{y}_{i,j} - V(i,j-1)\Delta^{y}_{i,j-1}\$
Where
\$U(i,j) = ...
- 185
7
votes
2
answers
2k
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Magic Square (Python)
Problem
Write a method to return a boolean if an input grid is magic square.
A magic square is a \$NxN\$ square grid (where N is the number of cells on each side) filled with distinct positive ...
- 3,477
7
votes
3
answers
254
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Project Euler #5 (LCM 1 - 20) Follow up
I'm actually spending time on it, unlike the first time and going through, understanding and implementing the several suggestions I've landed on two different approaches.
Approach 1: Employing Java 8 ...
- 9,809
6
votes
2
answers
107
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Code to measure the length of binary numbers in terms of English nomenclature
"ONE" and "ZERO".
The basis of this project is in this
video -> links to his code can be found in description
In it the speaker asks you to check his math; I wrote my own code and then compared it ...
- 69
6
votes
4
answers
599
views
Pascal Triangle calculation with BigIntegers
On a well known programming challenges website(CW) there is a Kyu2 eggs height problem that can be solved utilizing a variation of Pascals Triangles properties.
The problem asks to solve ...
- 160
6
votes
4
answers
1k
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Sum of digits in a^b
I'm trying to calculate a problem which requires sum of digits in \$a^b\$, where \$0 \le a \le 9\$ and \$0 \le b \le 4000\$.
I have seen various other posts similar to this, but I haven't acquired ...
6
votes
1
answer
781
views
Linear algebra, reduced row echelon form - function 1
This is a derivative post from here.
This is just a general review, so the question is the same:
Is there something...
That you would consider as a bad practice and why?
That is just bad in some ...
- 248
6
votes
1
answer
620
views
Project Euler #5 (Smallest multiple) in Swift
I found this one a little bit easier than the previous problems, but I was already familiar with the GCD/LCM formulas.
...
- 25.2k
5
votes
1
answer
65
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Exploring the space of 8 parameters of a physics problem to then be evaluated in ODE integrator as LSODA millions of times, efficently
there's a function in one of the scripts I've been working on that I really want to improve.
Disclaimer: Being honest, I'm not really very good at programming but I've been learning day to day and it'...
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5
votes
1
answer
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Linear algebra, reduced row echelon form
The code that I am sharing here for you to review today, is a segment of a JavaScript library that I am going to write as time goes by for fun. It is only the two functions in the following code:
<...
- 248
5
votes
1
answer
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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, 7, ...
- 153
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votes
4
answers
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Project Euler #5 (LCM of 1-20)
Challenge: 2520 is the smallest number divisible by 1 to 10 without any remainder.
What is the smallest positive number that is evenly divisible by 1-20?
Solution:
...
- 9,809
5
votes
3
answers
2k
views
Find smallest number of squares that sum to a number
Leetcode problem 279 “Perfect Squares” is:
Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...)
I wrote the following solution:
...
- 459
5
votes
0
answers
847
views
Recursive factorial calculations in Rust
I am trying to calculate very large factorials. I am looking to speed it up as 10000! takes approximately a minute and a half.
...
- 592
5
votes
1
answer
219
views
Optimising Funny Marbles
Problem statement is at http://www.codechef.com/DEC13/problems/MARBLEGF
Lira is given array A, which contains elements between 1000 and 2000.
Three types of queries can be performed on this array:...
- 395
4
votes
1
answer
604
views
Calculate the Euler-Mascheroni constant without the math module
The below code was written to generate γ, for educational purposes.
Single threaded, no functional zeroes required, no binary splitting(which can all be used to compute competitively like y-cruncher, ...
- 633
4
votes
3
answers
389
views
Calculate the centroid of a collection of complex numbers
In working on another problem, one component I needed was to calculate the centroid of a collection of complex objects. The well-known way to calculate this is to simply average the real and ...
- 64.9k
4
votes
1
answer
2k
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Circle - Line segment collision
I wrote an implementation of circle - line segment collision detection algorithm. Here is quick demonstration how it works:
And here is my implementation in Javascript using HTML canvas:
index.html
...
- 315
4
votes
1
answer
1k
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Followup: How do I optimize this Java cube root function for BigInteger?
Followup to How do I optimize this Java cube root function for BigInteger?
So I've tried several implementations of this algorithm. The version using only BigInteger sometimes results in a never-...
- 307
4
votes
1
answer
257
views
Brute-force search for solution to an unsolved mathematical inequality
From this Wikipedia article, the following unsolved problem is presented as a
result of Waring's problem:
It has been proven that a finite number of k exist, and so far none are known. The follow ...
- 3,770
3
votes
2
answers
5k
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Reverse int within the 32-bit signed integer range: \$[−2^{31}, 2^{31} − 1]\$ Optimized
LeetCode Problem
Reverse digits of a 32-bit signed integer. When the reversed integer overflows return 0.
Feedback
Optimized from beta code in the original question here. Based on this LeetCode ...
- 1,017
3
votes
2
answers
184
views
Find number matching range
I have code that checks the range of a value and sets a variable accordingly.
...
- 133