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?)

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1answer
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Determinant using Gauss Elimination

We had a question in examination to compute determinant of general square matrix. Now I had made the normal program using Laplace Formula of determinant, ie, recursive solution. Now I was thinking of ...
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2answers
549 views

Generating all permutations of 1 digit, 2 equal letters and 2 different letters efficiently

I created a function that generates all the combinations of 1 digit, 2 equal letters and 2 different letters. I reduced the numbers and letters to make it more easy to calculate: ...
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2answers
886 views

Project Euler Problem 21 in Python: Summing amicable numbers

Let d(n) be defined as the sum of proper divisors of n (numbers less than n which divide evenly into n). If d(a) = b and d(b) = a, where a ≠ b, then a and b are an amicable pair and each of a and b ...
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1answer
220 views

Generating all unlabeled trees with up to n nodes

I want to visualize all unlabeled trees with \$n\$ or fewer nodes, not just count them. First idea/attempt: Take a list of all \$n-1\$ node trees, then append a new leaf to every tree in every way to ...
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1answer
118 views

Project Euler problem 12 Python

I'm new to python and programming in general and I found Project Euler problems a good way to practice python. But my code is pretty slow. It seems to work, didn't wait long enough for the code to ...
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3answers
725 views

Draw sine wave going around a circle

I have used d3 to draw a sine wave going around a circle. This is the very first time I've used d3 or drawn a SVG and I'm fairly new to JS as well, so I don't know if I've overcomplicated it/if there ...
3
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1answer
82 views

Counting Divisors of a number with restrictions on the divisors

Given a fraction p/q, I want to count the number of unit fraction solutions $$\frac{p}{q} = \frac{1}{u} + \frac{1}{v}$$ with some contraints $$lower \le u \le upper$$ By manipulating the first ...
4
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3answers
818 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: ...
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1answer
114 views

Scaling decimal numbers up within bounds of limit

This code is part of a simulation and inputs will be positive values less than one and inputs are constrained elsewhere. The goal of the algorithm is to scale the inputs up to much larger numbers, ...
2
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1answer
46 views

Grade of Service Probability Function Python

Consider the following typical probability scenario: I defined this function to handle that scenario, I'm curious if Python has a more efficient method to handle this, or if this is the best way: <...
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3answers
1k views

Calculator of combinations without repetition

I am interested to find an absolute value (not an approximation) of "combination without repetition" for given \$n\$ and \$k\$, or \$\binom{n}{k}\$. The brute force solution would look like this <...
8
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1answer
471 views

Lagrange Interpolation over quadrilateral points

I've been working on a program which calculates, given a point and 4 surrounding points, the Lagrange polynomial, in order to interpolate a value. Consider that I'm not a mathematician and I better ...
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2answers
305 views

Find coprime numbers less than n

I get the coprime numbers less than n with the following algorithm: ...
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3answers
158 views

Return the product of the pythagorean triplet if a+b+c == 1000

I have found the answer to the problem I am trying to solve, but I am curious if there can be any improvements made to my code. ...
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2answers
1k views

Class Matrix implementation

Following the 18.06 Linear algebra course, I was curious to reinvent the matrix class and basic functionality, like \$PA=LU \$ decomposition, Gauss elimination, finding inverse matrix etc. Any ...
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2answers
688 views

Math Problem generator using switch statement ,Random method and arrays in Java

I m new in java and created a small project in which you have to solve random math problems there is three levels in it Easy, Medium , Hard, if you win or loss in game the message for three level will ...
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7answers
6k views

Python program to calculate GCD

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4answers
508 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 ...
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1answer
109 views

Convert numbers from base X to base Y

I recently wrote a piece of code to convert between two bases of X, (Where 26 > X > 0). I was mighty proud that I did this. And then I started wondering, am I using modern coding conventions/practices?...
4
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1answer
232 views

Method to return center items in a 2D array

I wish to have code that returns the center items of a 2d grid. Because I need an average value. The code I came up with does what I want (see the unit tests beneath it). But I think the code is ugly ...
3
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1answer
974 views

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 ...
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3answers
307 views

Project Euler #12 (Highly divisible triangular numbers) in Python 3.x

I'm a beginner to programming and just started python, I've been trying to work through Project Euler challenges. I wrote a program to solve Project Euler #12, which asks for the smallest number of ...
4
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1answer
176 views

Math Vector Header Library Templated on Data Type and Size

I have created a vector math header library where the size and data type stored are template values, and I'd like it peer-reviewed please. I have a few main questions: Will using my SizedVectorBase ...
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1answer
93 views

Find GCD of two numbers without using multiplication, division or modulus operators

If either a or b is 0 return the other number. If both even return gcd of a/2 and b/2. If either a or b is even divide it by 2 and return gcd of the pair. If a less than or equal to b, return the gcd ...
3
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1answer
176 views

Trigonometric Subplots with Matplotlib

The code consists of 4 functions that result in a figure with 3 subplots: a sine wave a cosine wave and the superposition of both (a bichromatic wave). I have shown in 4 ways, the first two are ...
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4answers
972 views

Power of two integers

Challenge: Given a positive integer which fits in a \$32\$ bit signed integer, find if it can be expressed as \$A^P\$ where \$P > 1\$ and \$A > 0\$. A and P both should be integers. ...
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1answer
451 views

Matrix implementation with Rank and Inverse calculation using Gaussian Elimination in Java

Disclaimer Some things that I must state: This is just for practice. I want to know the various algorithms in linear algebra in detail. I will not use this in a practical scenario. Except for ...
3
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1answer
116 views

Sum the remainders of ai%aj given an array “a”

Given an array of numbers, I am creating a table where, the cell at the intersection of row i and column j contains a number ai % aj. Numbers in the array can occur multiple times. Example: For ...
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1answer
56 views

Make a given number by adding given numbers

I have created a code that checks if a number can be made by adding different quantities of given numbers and if so returns the quantities. Is this the best way to do this or is there a more efficient ...
5
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2answers
328 views

HackerRank - Non-Divisible Subset

In this problem we are asked: Given a set, S, of n distinct integers, print the size of a maximal subset, S', of where the sum of any two numbers in it is not evenly divisible by k. Code My ...
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1answer
169 views

Greedy adaptive dictionary (GAD) for supervised machine learning [closed]

For my project in machine learning supervised, I have to simplify a training-data and I have to use this technique at page 5 of the document. Pseudocode algorithm My code (numbers are the steps): <...
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1answer
1k views

First n Happy Numbers

I wrote a piece of code to generate a list of \$n\$ Happy Numbers, would love to see how I can write it better. More information below. ...
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0answers
332 views

Matrix inverse by elimination

Because I had trouble in finding a reliable source on the internet for the matrix inverse algorithm using Gaussian elimination, I wrote one myself. Matrix.h ...
3
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1answer
810 views

Find LCM of two numbers

The problem is to find LCM of two numbers. I have tried to solve the problem in two ways. First by using the LCM formula : LCM (a,b)= a*b/GCD(a,b). Second, by ...
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7answers
7k views

Check if a given number N is a power of k

I am trying to solve a problem to check whether a given number N is a power of k. Example: Input 9, 3 > True // 3**2 = 9 Input 10, 2 > False Input 4096, 16 > True // 16**3 = 4096 I want to know ...
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2answers
137 views

“Disease Spread” challenge

Right now I'm solving this problem on codewars.com. I'm not sure about how to optimise the code further. Or is my algorithm inefficient? If it's an algorithmic issue, could someone help me how to go ...
3
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2answers
128 views

Search for solutions to quartic diophantine equation

I wrote this code to find the variables that will satisfy the diophantine equation (i.e. a^4 + b^4 + c^4 = d^4), for all variables belong to: (0 , 430000), and it takes forever to find the answer (I ...
2
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3answers
645 views

Project Euler 6: Sum square difference in Functional Programming (FP)

I wanted to practice functional programming (fp) without using any library but using vanilla JS only. So I took a problem from Project Euler: The sum of the squares of the first ten natural numbers ...
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2answers
132 views

Modular sum of square numbers in C++

So I've got an assignment which sounds like this: Given a number n, calculate the result of this sum, modulo 10,234,573: 12 + 22 + 32 + … + n2 This is what I've come up with : ...
3
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1answer
87 views

Program that finds the stretch factor of a parabola

Being a newcomer to C++, I decided to write a simple program that would accomplish a simple task. I settled on writing a program that, given the vertex and point on a parabola, find the "stretch ...
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0answers
470 views

Python palindrome function; is it possible to write it without using string conversion?

I hope this question is okay to ask on Code Review; this is a little function I wrote in Python 2.7.12 that checks if a number is a palindrome. It works fine but I'd like to know if there is a purely ...
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1answer
1k views

Navigating over a square spiral

I recently found adventofcode, but when I solved Day 3 in Python, I noticed that my code isn't looking very nice. The challenge is about navigating a hypothetical memory laid out in a square spiral: ...
3
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1answer
161 views

Maximal pythagorean triplet that sums to n

Write a function maxPythagTriple that accepts an integer n and returns the maximum product of three numbers that are both a ...
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1answer
77 views

Yaw (Z-rotation) angle linear interpolation without quaternions

I need to write a function performing linear interpolating between two Euler angles in 2D, perfectly without the use of quaternions as conversion seems to be an overkill for such a simple task. Here'...
3
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0answers
54 views

“Academic interest” implementation of a Finite State Machine

Context I'm playing around the concept of a Finite State Machine. While I understand the basic principles behind it, I want to implement a simple, yet generic class which could be reused in the ...
4
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1answer
147 views

Drawing spirals on virtual whiteboards

I have it set up so I place my mouse in the center of where I want the spiral to be, then I press enter to start the program, then define the radius initially and how much it grows each time it goes ...
5
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1answer
958 views

Extending Polynomial Class with math operations

Background After seeing a random coding interview question "write a program that can take the derivative of a polynomial", I decided to solve the problem using an OOP approach in Python. Then, I ...
5
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1answer
3k views

Hidden Markov Model with Viterbi

I have a Hidden Markov model class with basically a single method: getting the best parse of a sequence of input tokens based on Viterbi. While I have no hardcore benchmarks, I'd love some pointers ...
4
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1answer
130 views

Rare binary numbers

Rare numbers are the natural numbers in their binary forms in which there aren't two (or more) ones next to each other. Make a program that will give the N. rare number! For example: In case of N =...
5
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2answers
388 views

Find numbers that are palindromic in consecutive number bases

I want to generate numbers which are palindromic in three or more consecutive number bases in the most optimal, fastest way (up to some range). I do not count trivial one digit palindromes. (...