A hash table is a data structure used to implement an associative array (a structure that can map keys to values). It uses a "hash function" to compute an index into an array from which the value can be found.
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Kattis Issue - Animal Classifcation #2
Due to severe code-evolution i will repost this question here! The original can be found here : Kattis Challenge - Animal Classification
I'm new to competitive programming and C++ in general. I ...
3
votes
1answer
19 views
A set of functions that supports a spell checker
This is a program that loads a dictionary into a hash-table, and spell checks a text file provided as a command-line argument. The dictionary is formatted as such (just alphabetically):
...
0
votes
1answer
18 views
Optimize hash OCaml
I am running a simple OCaml program which opens a CSV file with a pseudo dict-reader and hashes "key" + "value" (where key and values are strings). Then some counts are evaluated on the hashes (but it ...
2
votes
2answers
82 views
Remove a key from list of hashes
Suppose my milestone is this:
milestones = [ {state: 'unavailable'}, {state: 'arrived'}, {state: 'completed'} ]
I want to remove all the ...
2
votes
0answers
40 views
HashMap with Binary Search Tree for Chaining
My friend was asked to implement a hashtable with a binary search tree. I tried practicing it myself, and it turned out to be very verbose. Need suggestions to clean this up!
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2
votes
3answers
55 views
Optimizing Java SHA-512 String-to-Hash Generator
In an attempt to learn Java and SHA-2 I created a very simple String-to-SHA512 generator. Here is the code:
...
3
votes
1answer
47 views
Merging hashes, summing values that have the same key
I'm trying to group by keys in an Array of Hashes in the following form and add their totals. Maybe with #map and #reduce/#inject. I know there is a more compact way to do this.
Given I have
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2
votes
3answers
290 views
Simple Chaining Implementation of HashMap
I'm practicing writing my own simple version of a Java HashMap. I don't have much experience with generics in Java.
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6
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1answer
70 views
Calculating protein mass
This question is part of a series solving the Rosalind challenges. For the previous question in this series, see A sequence of mistakes. The repository with all my up-to-date solutions so far can be ...
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0answers
61 views
custom hash table<K,T> that take responsibility to assign hashcode/index
Introduction
I try to create a game engine with component-based architecture.
There are many type game components and different game systems.
For example, the components can be
Com_HP (health), ...
3
votes
1answer
70 views
Implementing clearTable, grow and shrink on a hash table
I've gone through previous questions about implementing hash tables in python, but I have something little more specific. I am handling collisions with linear probing, and I want to grow/shrink my ...
8
votes
2answers
105 views
Hash table OOP implementation in C
To brush up my C I decided to do some OOP programming in C. I have never tested this before, but I was curious to try it since seeing an example of it a while ago. I decided to implement a simple hash ...
1
vote
1answer
133 views
Merging two hashes with the mean values of each key if both hashes exist
There are two methods, hash1 and hash2, that return hashes or nil. The hashes have the same ...
1
vote
2answers
231 views
Merge array of hashes, keeping duplicate values as arrays
I am working on a Ruby gem to pull data from the Wikidata API. The data is deeply nested, as it contains a lot of repetition.
I have written a piece of Ruby (sans Rails) code that enables an array ...
4
votes
2answers
81 views
Is this the right way to implement a simple hash table in C++?
Does this look like a proper implementation of a hash table in C++? Any errors anyone can find?
Thanks in advance (:
...
1
vote
0answers
108 views
Implementing a HashTable in Objective-C
I am trying to implement a hash table in Objective-C. I did some testing and the implementation seems to work. I am using an NSMutableArray to store linked lists ...
9
votes
3answers
2k views
Simple C# HashTable Implementation
Haven't put one of these together since college. How does this look overall?
...
5
votes
1answer
58 views
2
votes
1answer
51 views
Displaying a String array in tabular format
I have an array of strings called theArray. All strings in theArray are of length 20. I wish to display this array in tabular ...
0
votes
1answer
39 views
NestedHash Class
I want to make a Ruby nested hash table class to avoid repeating ugly code and to keep my programs as true to the OOP paradigm as I can. Are there any ways to make this class definition smaller and/...
1
vote
1answer
103 views
Creating a dictionary
I have a Ruby programming task. My code passes all the rspec requirements, but I am not sure if I've done it in the right way. And I'm not quite sure why I need ...
2
votes
1answer
54 views
4
votes
4answers
942 views
Python Hash Table Implementation
I'm attempting to implement a basic hash table in Python using only lists. Any tips would be appreciated (including better hash functions).
I intend this to handle collisions with separate chaining.
...
2
votes
1answer
2k views
Convert Multivalued map to HashMap
I have a Multivalued map (javax.ws.rs.core.MultivaluedMap<String, String>) which I want to convert to regular HashMap so I got below code:
...
3
votes
1answer
213 views
Hackerrank challenge - Dictionaries and Maps in Erlang
This question is really similar to an existing one in Ruby. So the task is also the same: Day 8: Dictionaries and Maps!
The problem is that on Hackerrank my solution only passes the first and last ...
-3
votes
1answer
424 views
Mapping phone numbers to names [closed]
Problem description:
You are given a phone book that consists of your friend's names and
their phone number. After that you will be given your friend's name
as query. For each query, print the ...
4
votes
2answers
731 views
Hackerrank challenge - Dictionaries and Maps
This is a solution for the Day 8 hackerrank.com challenge. The basic idea of the challenge is to create a mapping of names to phone numbers based on the the given input, and later look up the phone ...
0
votes
2answers
57 views
Adding polynomials represented as maps
I'm using maps to represent a polynomial.
The key is the exponent and the value is the coefficient : Map(exp -> coef)
e.g. ...
5
votes
2answers
48 views
Refactoring if statement based on a hash key
I have to call Article.to_draft/to_archive/publish method depending on the presence of the ...
4
votes
2answers
201 views
Dictionary implementation using hash table in C
I have written the below code which loads the dictionary and checks if the given word is present or not.
The implementation is using a hash table with a chained linked list.
In regards to the hash ...
3
votes
2answers
437 views
HashMap or associative arrays in C
I am trying to implement an HashMap in C. I am trying to used a linked list style of interfacing to make adding and removing keys easy and efficient. Searching is ...
5
votes
0answers
22 views
Variation of the internal PHP hashtable
I'm working on a PHP extension in an attempt to learn some C. I've implemented a variation of the internal PHP hashtable, which uses a lookup table and a separate bucket table. The lookup table simply ...
6
votes
2answers
76 views
Unicode-capable symbol table (N-way search tree with hash buckets)
As in my previous question, this module is coupled with its own testing framework.
As a symbol-table for a Unicode-capable programming language interpreter, I decided to combine the 3 types of ...
6
votes
4answers
598 views
Hash table and linked list implementation in C++
I'm trying to improve my understanding of inheritance and template classes in C++ so I coded a hash table (see compilable source code below).
I would be greatly appreciative of any comments on how to ...
6
votes
1answer
129 views
Remove a key from a hash table efficiently
I am trying to remove a key from a hash table, which is built using linear probing. Removing a key works fine but I know I need to rehash a portion of the table after the removal but my method down ...
7
votes
2answers
384 views
Trie key/value store implementation comparing with HashMap
I have implemented a Trie-based concurrent key/value store using hashcode similar to HashMap.
It is something like, if your ...
3
votes
1answer
572 views
Hash function for strings
Implementation of a hash function in java, haven't got round to dealing with collisions yet.
I tried to use good code, refactored, descriptive variable names, nice syntax.
My code must be efficient ...
1
vote
1answer
268 views
Hash Map Library for any type (Void Pointers)
This is a hash map library for C that stores void* pointers with char* strings (null terminated) for keys
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10
votes
1answer
104 views
ConcurrentDecayingHashMap<K,V>, a concurrent decaying HashMap
I wrote a wrapper for Java's ConcurrentHashMap that enables you to add a decay time to inserted values, meaning they will be automatically removed after the given ...
3
votes
2answers
287 views
Using EqualityComparer to find contained value
While searching for a method in HashSet which allows me to actually find an object in \$O(1)\$ (not just Contains, I need the ...
4
votes
1answer
34 views
Optimizing “complex” iteration over Map with auxiliary maps
This will be tough to explain. I am implementing a tool to support RFC6020. But when it comes to the Choice Statement, things get weird.
For the sake of better understanding, I have to remember you a ...
3
votes
0answers
211 views
HashMap and HashSet classes for ES6
The new EcmaScript standard, ES6, contains specifications for Map and Set built-in classes. Each of these collections treats an ...
3
votes
1answer
50 views
Creating simulated items sold at a store into a hash
I am writing code that creates a hash for a store that has an item, price, and sku. The hash is inserted into an array. I also create another hash based on the sku that holds the amount of inventory ...
1
vote
1answer
65 views
Gathering metadata on files in GitHub
I am a relatively new programmer and am currently working on something with the egit GitHub client library which requires me to iterate over a bunch of values and if a condition is met, add a bunch of ...
3
votes
1answer
94 views
Constructing NewsArticle objects from a database table
This class seems to be able to represent the data stored in any possible database table:
...
12
votes
3answers
2k views
HashTable implementation in C++
I made a simple hash table and I was wondering if there was any way to increase the efficiency of search times. My table class is called Dictionary, because C# has ...
2
votes
1answer
65 views
My own implementation of an hashtable
This is my own implementation of an hashtable. I would like to receive some reviews or some feedbacks.
...
2
votes
1answer
113 views
(Y.E.S.E.J.) Yet Another Singleton with Enum in Java
I have a Java class which has to be generated only once for all the objects that I have - it is a small program. This singleton class holds a mapping of characters. I Googled stack overflow and found ...
8
votes
3answers
358 views
Initialize a hash with all 0 values based on two arrays
Given two arrays (for instance a list of people and a list of subjects), I need to initialise a Hash with all zeros for all possible combinations of these two ...
4
votes
3answers
538 views
