Questions tagged [algorithm]
An algorithm is a sequence of well-defined steps that define an abstract solution to a problem. Use this tag when your issue is related to algorithm design.
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Much more efficient trisexual genetic algorithm for TSP in Java
This time, I have made the previous version of the GA for TSP run faster by around the factor of 6+. The idea is to cache the tour costs with the actual tour objects and cache the hash codes of each ...
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Genetic trisexual algorithm for TSP in Java
(A more efficient version of the GA.)
This is my the very first take ever on GA:
GeneticTSPSolverV1.java:
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Golang solution to CTCI 1.2: Check whether two strings are permutations of each other
Just started learning Go recently. Did some questions from Cracking the Coding Interview book. Wrote the solutions in Go. Let me know what you think.
https://github.com/samjingwen/ctci
Below is ...
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The shortest path between airports
Airlines need to provide their customers with flights to every corner, so they need an app that allows them to do so. The customer must be able to transfer when there is no direct connection.
The ...
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Encryption and Decryption in C
I have written a program in C, which encrypts and decrypts a c-styled string (const char *) and print the result to stdout. It ...
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Algorithm Challenge: Fuzzy Search
I recently took part in an algorithm challenge to create a Fuzzy search with the following criteria:
Given a set array, create a function that receives one argument and returns a new array containing ...
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Genetic TSP in Java with graph expansion
This post presents my take on TSP (travelling salesman problem). The idea is to:
Take an input node i,
Compute the entire graph ...
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Leaky Bucket Algorithm with no Queue
Basic implementation of a leaky bucket, the idea is you call it by saying I will allow e.g. 5 login attempts per 60 seconds.
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Rijndael Cipher in C++ (128bit AES)
I am a hobbyist and do not work in the industry but do have an interest in programming an cryptography. I decided to have a go at writing a 128bit implementation of AES in C++. This is my first ever C+...
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Traditional vs. bidirectional Dijkstra's algorithm in C
I have this CLion project on GitHub. It constructs a directed, weighted graph consisting of 100 thousand nodes and 500 thousand directed arcs, picks two random nodes, and computes the shortest paths ...
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Percolation threshold simulation using C++
I am studying Algorithms by Princeton University. The first week assignment is to simulate percolation by using Java.
https://coursera.cs.princeton.edu/algs4/assignments/percolation/specification.php
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Group a list of objects by property and remove the first value from each group
I have a list of Students and I want group this list by the property NAME, to sort each group ASC by the property ...
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Comparing two general LCA algorithms in Java
Now I have two algorithms solving a problem: given a general (multi-way) tree, and any array of node names, find the the node that is the deepest common ancestor.
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General (multiple nodes) LCA queries in Java
I have an algorithm for computing multiple node LCAs (lowest common ancestor):
TreeNode.java:
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Sorting in linear time using Trie Data Structure
I have written an article on a new way of non comparison sorting and I want it to get peer reviewed. The sorting algorithm uses Trie data structure to store digits of numbers as nodes and iterating ...
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gradient descent implementation
I am attempting to implement my neural net for a fully connected network configuration. I don't know much about neural networks and ai, so the implementation is not great and may contain errors ...
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Update user's experience points
I have a private method in my class to update user experience.
First of all, I create giveExp based on contentLength (...
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Synchronization \ backup of directories and files (Python)
stackexchange members. I'm just learning to write. I set myself a task a few days ago and today I completed its implementation. The task was to create a "backupper" (I was inspired just by ...
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Most frequent element in an array, return lowest if multiple
I have been learning C++ for the past 2 weeks.
Following is a problem I solved from Hackerrank. I am somewhat unsure if it's the correct way to solve this, even though I got the desired output. How ...
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Replace string with another string in C
I have written a program that replaces a given c-string with another c-string. My code works well with small files but takes too much time while working with large files (50 Megabytes and larger).
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Time complexity of several methods of reversing a domain name string
Note: I'm aware of this existing post which is similar. However, it does not address all my questions sufficiently.
I have the following three functions, all of which do the same thing: reverse a ...
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LFU Cache implementation in Python 3
Need some feedback on this implementation of LFU cache in python3.
Original problem : https://leetcode.com/problems/lfu-cache/
Would really appreciate some feedback on readability, understandability ...
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Sequential Search - Recursion
I have written this program to search for a value in an array using sequential search. And well, I've been trying to implement the same algorithm using recursive structure. is this a good ...
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Karatsuba's multiplication
I am working my way through an algorithms course online, and the assignment is to implement Karatsuba's multiplication algorithm. I am also trying to practice C++, so I wanted to implement it in that ...
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Priority Queue for D* Lite
So, I needed a priority queue for D* lite and I wanted to know whether this is an acceptable implementation or not.
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Finding the largest value in array - Recursion
I know this may be a silly question (I'm just learning about recursion, and I think there are still things that are still not clear to me.), but... is this a good implementation of a recursive ...
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C++ merge sort implementation (looking for advice)
I am trying to practice C++, so I decided to implement canonical algorithms in C++ as a way to learn best practices and idioms of the language.
I started with merge sort. How could I improve this ...
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Binary Search Tree - My own version of delete function
Well, I am recently learning data structures and algorithms and I came across the Binary search tree and decided to first time use my own logic to make the delete function. I have not come across a ...
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Manacher Algorithm in Haskell
Please review the manacher algorithm in haskell. Find the longest Palindrome in a String.
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Count lengths of constant subarrays
I have an array assuming discrete values. For each value, I am interested in how often it is assumed in a row.
For instance, if my array is ...
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Guessing game - Too high. Too low
I will post 2 scripts that are doing (supposedly) the same thing. First one is the script i created, second one is the solution from the course.
What would you consider wrong (if anything) with the ...
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Which fruit fall onto my house?
I am following a question on a programming challenge website (here's the original reference). What I have is a house (start & endpoint) and some types of trees at their respective location points. ...
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Array of values determine if they vary wildly (or not) using z-score
Determine how 'spikey' graph data would be
I want calculate if a list of random set of unsorted numbers present themselves as varying greatly over the one value to the next. The thought is to be able ...
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Searching for a performance bug in a C++20 pathfinding algorithm (NBA*)
(See the next iteration.)
I have this pathfinding algorithm:
DirectedGraph.hpp
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Maximum length of a row made up from given dominoes
Given a set of dominoes, find the maximum length of a row that can be made using some of those dominoes. Rotating the dominoes is allowed.
Recall: A domino piece consists of 2 numbers from 0 to 6 (e....
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Wordle color algorithm in JavaScript
A lot of Wordle clones get the tile-coloring algorithm wrong: for example,
if the word is BURNT and you guess TOAST, the colors should be ----G (not Y---G)
if the word is MAXIM and you guess MAMMA, ...
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Optimizing Code for Spectral Gradient algorithm in Python
I am building an algorithm to run proximal spectral gradient for research purposes. The code is almost in its finalized step, but the runtime of the code is slow. I hope to seek your professional ...
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Create a custom split method that keeps the delimiters in Swift
I have implemented a custom split method that replicates the original functionality of the collection's split method in Swift and keep the delimiters (element separator). After a lot of trial and ...
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Is this implementation of the First Come First Served algorithm the most appropriate? How can it be improved?
I have developed a program that implements the First Come First Served scheduling algorithm. The total number of processes is read directly from the input standard, and for each process the arrival ...
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Encoded string algorithm with given rules
Looking for general feedback and if there is a solution that can reduce the time complexity from the current O(n2)? Thank you.
Problem Statement
Consider a string that consists of lowercase English ...
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Python functions that calculate first n terms of a given order of Fibonacci sequences
I have written two functions that calculate the first n terms of a given order o of Fibonacci sequence, and return the result as ...
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Huffman coding implementation in java
I wrote a simple huffman coding algorithm for learning and practice. I just used the technique given on the wikipedia page.
Could you tell me my missing points and mistakes?
Node.java
...
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Median cut algorithm
I have implemented a simple version of the median cut algorithm. It takes a vector of Color structs representing pixel in an image. I also use the ...
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How to optimize `push` and `pop` in this tree list algorithm?
So based on this question and answer, which is based on this answer, I have abstracted it out into a reusable module. Basically it is the TLList class, with a ...
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How to remove duplication in this array/tree generating function?
Here we have the following code.
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Related to DSA: Find longest common prefix
The objective of below code is find longest common prefix from trie DataStructure which is written in Java.
Code:
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Dijkstra's Shortest Path Algorithm
Is there anything I could do better in this Dijkstra's Implementation. This is my implementation of Dijkstra after understanding the concept. I used hash table wherever possible to have faster access
<...
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How can I avoid duplicate processing of vertices in the priorityqueue with Dijkstra?
So everytime a neighbors is discovered with an improved distance, it is added to the priorityqueue with the new distance (so it can be used in the right order). This means however that the old entry ...
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Greedy number partitioning algorithm
I have two functions in Python that do the same thing: they partition a set of items of different sizes into a given number of subsets ("bins"), using an algorithm called greedy number ...
