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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Implementing Dictionary using hashtable with chaining

As mentioned in homework6, the homework problem is: Part I (6 points) Implement a class called HashTableChained, a hash table with chaining. ...
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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: ...
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43 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 ...
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121 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? ...
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1answer
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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 ...
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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 ...
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HashMap of pseudo variables of any type [closed]

I am writing simple variable system in Scala. I need a way to nicely hold these AnyVars and access them by their string names. I have this object called context to ...
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4answers
177 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): ...
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77 views

Custom ConcurrentHashMap for ints

I've implemented a concurrent hash map for int primitives. ...
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2answers
107 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 ...
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3answers
200 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 ...
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1answer
32 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 ...
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101 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. ...
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1answer
35 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 ...
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1answer
74 views

ConcurrentHashMap Implementation

I have written a simplified version of my own MyConcurrentHashMap. I tried to make use of a Lock[] array for ...
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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 ...
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1answer
54 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 ...
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35 views

Passing around and using Python dicts [closed]

I have an Excel file - a profit spreadsheet - which has one tab per product range. The tabs are defined and named, but apart from that, the file contains no data (yet). I wish to use ...
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1answer
74 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 ...
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1answer
112 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 ...
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1answer
123 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 ...
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2answers
52 views

Count of words in a mutable Map

The function should get some text on input and return a map in a following format: ("word1" -> 1, "word2" -> 2 ...) The keys are words from text and the ...
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Hash table with “Time To Live” elements

Recently, I got a very interesting task: to realize the hash table that works in multi-process server in common memory, each element of which must have a TTL property. It was suggested to implement ...
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1answer
108 views

Safely storing Azure Topic clients in concurreny dictionary

I am trying to optimize the usage of TopicClients in my app. The instance is originally covered by interface and passed by IoC, so the IoC will dispose it at the end of the program life cycle. This ...
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2answers
113 views

Recursively merge dictionaries with generic types in C#

I am looking to implement a method that is capable of merging 2 dictionaries using generics. I've seen several great answers on SO already, but none handle the case of nested dictionaries. As in, what ...
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1answer
87 views

Reducing the size of JSON objects

I wrote a function to reduce the size of JSON objects that works simply by turning every associative array into an indexed one, and moving each property's name to the first row of the data array ...
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1answer
231 views

Shakespeare and dictionaries

The following snippet will return a list containing the words in all of the works of Shakespeare: ...
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2answers
49 views

Python script to read CSVs and regroup it into the data types I need

This code does the following: Read CSV file and determine sub_type based on series_desc. Turn row into dictionaries ...
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2answers
108 views

Creating a dictionary from two lists

I have working code here which takes two lists and turns them into a dictionary with the first list being the keys and the second being the values. If the keys exceed the values the value "None" will ...
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2answers
47 views

Comparing two columns in two different rows

I want to go through each line of the a .csv file and compare to see if the first field of line 1 is the same as first field of next line and so on. If it finds a match then I would like to ignore ...
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327 views

The most efficient way to merge two lists in Java

I am looking for a way to merge two files with a list of distinct words, one word per line. I have to create a new txt file that would contain all the words of the first list and all the words from ...
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277 views

Return all words which have their reverse present in a string

Problem Statement: Given a string of words return all words which have their reverse present in the string as ( (word1 , reverseword1 ) , (word2 ,reverseword2) ) Example Case: Input: ...
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1answer
62 views

Rename subkeys of nested dictionary dynamically

My nested (ordered) dictionary looks like this: ...
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3answers
53 views

Intersection of subset between two lists of dicts

I want to find the intersection of two lists of dicts. Note that equality—i.e.: what is to appear in the intersection—is given by which keys they must have equal. See the ...
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2answers
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Scraper for words from Wiktionary

I wrote this code in Java using the Jaunt library. The program scrapes all words from Wiktionary from category "English_uncountable_nouns". And after save each world to text file. I am not sure that ...
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138 views

Build a dictionary based on split string

I've written a simple script that takes a string filled with brackets and strings and builds them to a dictionary. Example Input: ...
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1answer
70 views

Denormalizing an OrderedDict to CSV

Cross post from stackoverflow, as suggested. I have an ordereddict, and I need to store it in CSV file. Input: ...
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2answers
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61 views

Restructuring nested maps

I am in the process of making an assembler and one of the needed steps is actually getting the opcode from a table. However, the instruction set I'm working on has a handful of different addressing ...
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Add 100 to all values in nested dictionary

I want to change all values in a multidimensional dictionary. I have written this line of code, which does what I want it to do and I am trying to find out if this is the optimal way or just some ...
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Dictionary foreach loop with multiple occurences

A little look on what are Dictionaries: dictWordCounter<string, int> dictWordPercent<string, double> topTwentySeven<string, double> ...
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643 views

Convert a string into a dictionary

I have a string like "food | dairy | milk". The string may consist of more or less words. How do I turn it into a dictionary ...
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71 views

Inverse mapping of a dictionary

For the below question picked from here: Write make_inverse_dict(d) that returns a new dictionary with the 'inverse' mapping. The 'inverse' mapping of a ...
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110 views

A map class based on an AVL tree

Here's an implementation of a class which is similar to std::map, but it's not a complete/identical implementation. I know C pretty well, but am a beginner with ...
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1answer
101 views

Numerate every item in dict

I have a .json file with a complex structure: dict in a dict, it has no constant structure and is dynamically changed. The goal is to make new dict where the keys are numbers of hierarchy and values ...
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1answer
98 views

Self Implemented Hash Map Performance

I have written two hash map implementations, one that stores Vertices and one that stores self implemented vectors of Edges. They are all fully functioning, however in my application they are quite ...
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2answers
86 views

Forming a dictionary where all values are only conditionally set

I have lots of dictionary keys with conditional values, ternary in this case: ...
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873 views

Checking for any character common to two strings — Go is 50× slower than Python

I decided to learn Go, knowing Python. My approach is by solving easy problems like this one: You are given two strings, A and B. Find if there is a substring that appears in both A and B. ...
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Data loading Hash Map

I'm trying to improve my code's performance, and I've found an area where the execution time is being significantly increased. I've had a look through the code but I can't see how I can improve it. ...