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.

learn more… | top users | synonyms (1)

1
vote
1answer
38 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
40 views

Basic toy hashtable

I wrote a minimal implementation of a hashtable in python as an exercise. ...
4
votes
3answers
79 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
57 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: ...
1
vote
1answer
72 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
186 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
247 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
44 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
40 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
54 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
106 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 ...
4
votes
0answers
19 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
51 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
153 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
51 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
267 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 ...
2
votes
0answers
73 views

Jacob's Ladder compression [closed]

I'm currently interested in a logical decay algorithm which will need me to have the correct coordination of 3 bytes. I have 2 of them, initially. After that, I have to get 2 from the one, but in that ...
3
votes
1answer
152 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
67 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 ...
6
votes
0answers
64 views

ConcurrentDecayingHashMap<K,V>, a concurrent decaying HashMap

I wrote a wrapper for Javas ConcurrentHashMap that enables you to add a decay time to inserted values, meaning they will be automatically removed after the given time. This functionality is ...
3
votes
2answers
227 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
31 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
64 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
33 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
60 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
93 views

Constructing NewsArticle objects from a database table

This class seems to be able to represent the data stored in any possible database table: ...
10
votes
3answers
834 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
45 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
83 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
221 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
323 views

Simple cache dictionary

I decided to write a simple dictionary to use as a cache: ...
3
votes
0answers
107 views

OOP paradigm implementation of a Dictionary data model

Here is the implementation of interface Dictionary using chained hash table class HashTableChained. Despite item 22* saying ...
4
votes
1answer
51 views

Unordered (hash) map for C

I am still working on basic data structures for C. Now I came up with a hash map: unordered_map.h: ...
3
votes
1answer
55 views

Ordered map for C using AVL tree

I was in the mood for some data structures and I decided to code up an ordered map using AVL tree. I will post only map.h and ...
3
votes
1answer
165 views

Duplicate integers in an array

Code shows duplicate values of integers in an array with indexes and the number of occurrences. Can you please critique my code and provide your thoughts on where I should improve my code? ...
1
vote
1answer
28 views

Capping values in a map while keeping one fixed

I'm working with some Clojurescript code that reacts to user input over three sliders. These sliders get stored in a map, and I need to make sure that the sum of all is <= a ...
5
votes
2answers
157 views

Find the rarest in a map

Write a method rarest that accepts a map whose keys are strings and whose values are integers as a parameter and returns the integer value that occurs the fewest times in the map. If there is a ...
5
votes
4answers
700 views

Finding the most common character in a string with a hash map

I created a method for finding the most common character in a string (using HashMap): ...
0
votes
0answers
89 views

Custom ConcurrentHashMap for ints

I've implemented a concurrent hash map for int primitives. ...
5
votes
2answers
201 views

Function that shortens a String based on a term/abbreviation mapping

I have a function that takes a description as a String and returns a shortened version of the description. The shortening is done by checking if a word matches the ...
4
votes
3answers
775 views

Most common occurrence of an int in an array

I am prepping for a junior level interview in C#. I am hoping I can get some feedback on how to improve my code to print the most common occurrence of an int in an ...
2
votes
1answer
65 views

Chained hash table implementation to store student's information

This is my implementation of a Hash Table to store information about a student. Everything seems to work as expected, but I'd like some feedback on the following: Is my style good? Is it easy to ...
6
votes
2answers
360 views

Hash table based key/value dictionary in C++ with murmur hash function, linked list buckets in 200 LOC

hashdic.h -- suggested for direct include or copy paste to your project. ...
5
votes
1answer
41 views

Dump hash in columns

I tried to answer the question "How to print a hash in Perl, such that 3 key value pairs are printed on each line?" like this. As I got an uncommented downvote, I'd like to ask: What's wrong with/How ...
4
votes
1answer
119 views

ConcurrentHashMap Implementation

I have written a simplified version of my own MyConcurrentHashMap. I tried to make use of a Lock[] array for ...
1
vote
3answers
101 views

Faster method for loading a hash table

I'm looking to make my code faster for loading a hash table. Any pointers would be appreciated. Below are my includes, the node def and the loading code. The dictionary loaded could be any *.txt ...
4
votes
1answer
76 views

Concatenating a SoundCloud Playlist Update JSON

I am currently working on an implementation of SoundCloud for a 3rd party iOS app, and as there is no SDK anymore I am doing all my calls via Alamofire. This is what SC expects you to send in your ...
2
votes
1answer
242 views

LRU cache design using dict and doubly linked list

Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the ...
3
votes
1answer
177 views

A minimal HashTable implementation

For an assignment, I wrote a minimal HashTable implementation (it only supports additions; no deletions). To resolve collisions, it uses Linear Probing (required by the assignment). I'm looking for ...
5
votes
1answer
161 views

Hash table for Coursera's algorithms course

I implemented a hash table for Coursera's Algorithms and Design class. I am looking for feedback on coding style and other improvements. I want to practice C++ coding but I see myself drifting to C ...