An algorithm is a precise plan (in the format of a sequence of steps) on how to solve a particular problem.
3
votes
1answer
64 views
Determining average of integers using quicksort
I was attempting an online problem given on a programming website which asked us to tell us the number of integers in a given list which can be obtained as an average of any two other integers in that ...
2
votes
1answer
42 views
Binary HeapSort and Ternary HeapSort implementation
This is my take on binary and ternary heapsort implementation for a university assignment. The code works but I wonder if there are any mistakes or things to improve.
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-1
votes
0answers
17 views
5
votes
1answer
56 views
Binary Search in Ruby
I want to write a search that raises an error if the list supplied is not sorted.
...
3
votes
1answer
64 views
Implementing a genetic algorithm to solve knapsack
I am trying to develop a genetic algorithm to solve knapsack problem(0-1). I am new to algorithm and programming as well. Here is my code and it works but I would like to know your suggestions of how ...
3
votes
2answers
118 views
Calculating sum of manhattan distances in a sliding puzzle
I would like some feed back on a method which calculates the sum of Manhattan distances for each tile in a sliding puzzle to its goal position in the goal puzzle.
Here is the code:
...
6
votes
1answer
44 views
Tracking (uniform spacing) between 2D elements
The problem I am solving:
I select multiple 2D SVG elements in an editor(the elements
are in arbitrary positions on my canvas).
I run the function ...
3
votes
0answers
25 views
BFS and DFS tree traversal
I posted some code as part of an answer to another question and I thought it would be a good idea to get that code reviewed also.
Any comments are welcomed, but I am mostly annoyed by ...
1
vote
4answers
83 views
0
votes
1answer
37 views
Speeding up Mersenne prime generator
I am writing a program to calculate Mersenne primes. This code works, but it is so slow:
...
7
votes
4answers
282 views
Effectively calculate the result of geometric series
Given \$f(n) = 1 + x + x^2 + x^3 + \ldots + x^n\$ and the fact that computers take more time when multiplying two numbers than when adding, how can we work out the result with greater efficiency?
...
3
votes
1answer
32 views
Test if two nodes in binary search tree are cousins
Cousins are nodes at the same level of the tree, with different parents.
They don't have to share the same grandparent.
My solution depends on having a binary search tree with unique elements.
This ...
3
votes
3answers
46 views
Hexadecimal to string without C++ standard library functions
For the purposes of this code review, I will use the standard library, but pretend that <cstddef> is <stddef.h>, ...
4
votes
1answer
35 views
Optimization of Barnes-Hut Multithread Insertion algorithm
I'm currently working on optimizing a Barnes-Hut implementation (connected to a previous post I did) and I need help to optimize it further.
After some testing, the main problem appears to be in the ...
13
votes
1answer
107 views
Advanced and Detailed Minesweeper Probabilities
In an earlier question, I showed my code for calculating the mine probability for each and every field in a Minesweeper board. But it doesn't stop there. In that very same Minesweeper Analyze project, ...
4
votes
1answer
63 views
Functional Knapsack Problem in Python
This is the knapsack problem from rosettacode.org:
A tourist wants to make a good trip at the weekend with his friends. They will go to the mountains to see the wonders of nature, so he needs to ...
4
votes
1answer
37 views
Graph (adjacency list) for BFS and DFS in Golang
I am trying to implement a Graph data structure in Golang and choose to use adjacency list representation. When starting to implement adjacency list, I have an idea ...
3
votes
2answers
128 views
Implementing a genetic algorithm to solve the Diophantine Equation
I am trying to implement a genetic algorithm to solve (Diophantine Equation).
For instance, a + 2b + 3c + 4d = 90 where a, b, c, d are positive integers.
After reading some books and following ...
5
votes
3answers
94 views
Finding the closest value in a collection in a game-server plugin implementation
I have an array of a instances of an enum type. A random double variable is initialized with a value between 0.... to 1, and should be used to get the closest ...
6
votes
2answers
94 views
Summator simulation
This is a reference implementation of a summation unit. The algorithm used is a most straightforward carry-propagation. If necessary, a test driving code could be provided.
Few notes for the ...
5
votes
3answers
65 views
Bubble sorting in C
I've been into algorithms lately, so I wanted to apply a simple algorithm using a language of my choice, which was C in this case.
I've implemented the bubblesort algorithm (for strings) in a simple ...
3
votes
2answers
101 views
Encryption-decryption method
My encryption algorithm
I'm using this algorithm in order to encrypt notes users save on my site:
...
3
votes
1answer
46 views
Solving the Shortest Path problem (little bit of TSP, too)
Some background info:
I'm working at a shipping company and the company's web developer has been fired a week ago. My boss knew that I had some knowledge in web development, so until we get a new ...
3
votes
1answer
32 views
Iterative Flood Fill implementation in C [closed]
I am trying to implement an iterative version of flood fill in C:
...
4
votes
1answer
51 views
Detecting connected acyclic through Tarjan strongly connected components variant
I want to verify that a given directed graph is connected and acyclic (DAG). I have implemented a modification of the Tarjan's strongly connected components algorithm in imperative style (as the ...
10
votes
3answers
1k views
Dining Philosophers Algorithm
Please visit the http://en.wikipedia.org/wiki/Dining_philosophers_problem for algorithm discussion.
I have written below java program to solve this problem by Arbitrator solution algorithm mentioned ...
3
votes
1answer
64 views
3
votes
2answers
91 views
Game of Life generation procession algorithm
I've tried to make Game of Life in console and this is the algorithm I used to generate new generation:
...
2
votes
2answers
66 views
Ruby Mod 11 implementation
I wrote this Ruby Mod 11 (perhaps it's a bit generous to call it that) implementation to validate Brazilian CPF documents, which use a Mod 11 algorithm. CPF format is a 9 digit number followed by two ...
5
votes
4answers
125 views
NULL-eating / elimination version of fgets() in C
I've come up with the following routine to read data from a file stream, but I don't want any NULLs in the stream to terminate the string early. This function will ...
4
votes
0answers
47 views
Equivalent binary trees (structure & values)
I am following the Golang tour and I have been asked to build a couple of functions to manipulate binary trees.
My code runs as expected, but I would like to know if I could further improve my code. ...
1
vote
2answers
92 views
Large arrays make runtime very slow
So I have the following code that takes the input of two arrays, and apply some queries to match elements from DBpediaClassesArray with elements from ...
4
votes
1answer
50 views
Zeckendorf numbers the Clojure way
I'm just getting into Clojure, and I wanted to make sure I am writing code the "Clojure way". The challenge I took on is Zeckendorf numbers (fairly trivial).
...
7
votes
1answer
102 views
Topological Sort and Graphing in Python 3
I wrote a program for DFS traversal, topological sort, find all vertices, and has_cycle methods.
Can you please suggest more elegant and eloquent ways for this program?
(Perhaps better ways to ...
5
votes
1answer
60 views
Summing up distinct elements in steps (follow up)
This is a "follow up" to an answer I gave on this question : Summing up distinct elements in steps
Here are the OP's requirements :
"My current task is to find a score from an array where the ...
6
votes
1answer
79 views
Check a collection of prices against an associated collection of minimum prices
I would like to find a more efficient way to solve this problem. My current implementation has 3 separate loops through the data.
I'm creating an algorithm to check a collection of prices against an ...
0
votes
2answers
102 views
Josephus Problem in Java
Problem
The Josephus Problem is a famous mathematical puzzle that goes back to
ancient times. There are many stories to go with the puzzle. One is
that Josephus was one of a group of Jews who ...
2
votes
2answers
23 views
Performance of RegExp vs Rune Loop
I was recently talking to someone about a function I wrote to mimic (very basically) the string interpolation function String.Format() found in the C# language. ...
5
votes
1answer
100 views
Groupby in NumPy
To avoid the XY problem, here is an example of what I need. Given the sorted integer input array
[1 1 1 2 2 3], I would like to produce the following slices, ...
4
votes
1answer
39 views
Stable partition in Numpy
In essence, I need to do a stable partition: All elements of the 1D np.array a that are present in ...
8
votes
1answer
75 views
Bitmap problem performance boost
Problem statement:
Input is a rectangular bitmap like this:
0001
0011
0110
The task is to find for each black (0) "pixel", the distance to the
...
2
votes
0answers
41 views
Circle Shadow Experiment
I'm trying to create a light system, with the midpoint algorithm and Bresenham Line Algorithm. I'm trying to redraw all the time (1 option) or redraw when I need to. When the circles are too big it ...
8
votes
5answers
494 views
Program for finding Fibonacci primes
I think it could have been designed with more object orientation. I don't like how one of my methods calls another from within the method, but I wasn't sure how to return the result because it is a ...
0
votes
1answer
78 views
Find number of inversions in a given array
Can you please give me a hint on how to improve performance of the following algorithm meant to find the number of inversions in a given array?
...
4
votes
2answers
136 views
Reverse Game HackerRank Ruby Solution
Problem Statement
Akash and Akhil are playing a game. They have N balls numbered from 0
to N−1. Akhil asks Akash to reverse the position of the balls,
i.e., to change the order ...
2
votes
2answers
51 views
Swap Kth node from beginning with Kth node from end in a Linked List
Given a singly linked list, swap kth node from beginning with kth node from end. Swapping of data is not allowed, only pointers should be changed.
This code is attributed to geeksforgeeks. I'm ...
7
votes
2answers
58 views
External / File-based mergesort
I've implemented an external mergesort to sort a file consisting of Java int primitives, however it is horribly slow (fortunately it does at least work).
Very little happens in the sort method: it ...
4
votes
0answers
26 views
Fowler–Noll–Vo hash function in Lua
I recently coded this FNV-1a hash function in Lua. Are there any apparent performance improvements that could be implemented?
...
2
votes
4answers
588 views
Sorting Algorithms
A group of basic sorting algos. Based on Algorithms, 4th Edition - Robert Sedgewick | Kevine Wayne. Just making sure all of my logic and everything is correct.
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2
votes
2answers
58 views
Find a triplet from three linked lists with sum equal to a given number
Given three linked lists, say a, b and c, find one node from each list such that the sum of the values of the nodes is equal to a given number.
For example, if the three linked lists are ...
