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.
3
votes
2answers
260 views
Data Persistence
I was wondering if I could get some feedback on the library I created to persist data online.
JitterPushDemo.java
...
2
votes
0answers
27 views
An intrusive chained Hash Table
I was interested in experimenting with some intrusive versions of common data structures,
so I've written this simple chained hash-table using the approach:
...
1
vote
0answers
11 views
Universal nested get/set for trees in Python
Based on this source, I've made the following universal get / set function, to make it possible to work on OrderedDict trees for example.
...
4
votes
2answers
159 views
Simple Chained HashMap
I am very inexperienced at C++. I wrote a Hash Map which uses chaining for collision resolution. I intentionally did not use smart-pointers, as the objective of this was to learn and showcase. I ...
4
votes
0answers
44 views
Mapping arbitrary Int values to a linear index space
This is part of a growing "primitive" tools collection here on github, and is the initial use-case for the IntArray for review here.
Often, when processing data, you encounter unique values that you ...
0
votes
3answers
81 views
Finding all integers in an array with odd occurrence
I am doing an interview exercise problem from here.
The problem is to find "all numbers that occurred an odd-number of times in an array".
Here is my high level psuedo code thinking:
Construct a ...
1
vote
1answer
68 views
Thread Safe Objects in CSharp - ConcurrentDictionary
I'm using ConcurrentDictionary to hold the records.. I'm reading files from the local system in parallel, to speed up the process.
Sample 1:
...
4
votes
1answer
69 views
Dictionary with restricted keys
I'm currently building some software that works with systemd unit files, and I've been trying to improve how we construct the unit files.
This is all running in Python 3.4
This first block is the ...
7
votes
3answers
113 views
Replace keys in values with key->values from same dictionary
I have a dictionary whose values may contain keys that are already in the dictionary. What we are actually talking about are parameters. Sometimes a parameter is defined by a number plus another ...
2
votes
1answer
40 views
LRU Cache Design using LinkedHashMap
This is a follow-on qestion from: LRU cache design
Revised Implementation
...
5
votes
2answers
76 views
5
votes
0answers
49 views
BiDirectional Dictionary (and its Mutable friend can come too)
I've attempted to implement a 1-to-1 dictionary in Objective-C. I'm probably missing some convenient methods that one might commonly want to use.
These are both declared in the same ...
1
vote
1answer
42 views
Simplifying the code with same list comprehensions
I have such method where:
primary_images is dict,
additional is ...
2
votes
1answer
64 views
Hash table with double hashing
I writing a hash table with double hashing. This code works ONLY with ASCII text files and finding the number of occurrences of each word in input file! Please point out mistakes and shortcomings.
...
2
votes
1answer
46 views
5
votes
2answers
59 views
VSTO Write Dictionary To Range Extension Method
I was hoping to receive some criticism on this block of code. I wrote it to write the contents of a dictionary to excel range in VSTO. It works well. I am interested to see how people could improve ...
1
vote
1answer
43 views
Filtering stocks by dividend yield
I have a dict of stock tickers (KEY) and a data point (VALUE; e.g. dividend yield).
I want to know which tickers have a value between a specified min and max value.
Given
...
5
votes
3answers
148 views
Optimize huge text file search
I have several huge 100MB text files that I need to scan through to pick out certain frame numbers which relate to a specific log packet of interest. My plan was to scan for these frame numbers and ...
3
votes
1answer
54 views
Hashing a struct in C
I'm trying to learn how chained hashing works, but can't get any further than this.
I think hashing works, but after finishing this little program, someone told me that what I have created so far has ...
1
vote
1answer
49 views
Handling overwriting of unique Dictionary values
I am working in C# to write a scheduling application for operations in a factory. I have a custom class Workday, with properties to represent a ...
1
vote
0answers
67 views
Hash Table Implemented by Javascript
I recently tried to implement a simple hash table using Javascript. Could anyone help me review my implementation?
...
2
votes
2answers
117 views
Counting a cycle
An interview question I got -
Each element of an int array points to the another element,
eventually creating a cycle. Starting at ...
2
votes
1answer
52 views
Iterating and fetching values from dictionary
Here is my dictionary:
c_result1 = {"1": {"time": "89.46%"}, "2": {"date": "10.54%"}}
c_result2 = {"1": {"money": "89.46%"}, "2": {"finance": "10.54%"}}
I want ...
3
votes
2answers
68 views
Ruby hashes of status counts
I have a method that takes a model object, reads through its children and returns a hash of status counts. It should only return a count on a status if one exists.
This method works, but I was ...
0
votes
1answer
66 views
A double mapped cache with WeakReferences for second key type
I needed a way to cache a large number of objects with two different types of keys.
In my case:
A String key represents my object in a serialized form. This way ...
2
votes
1answer
79 views
Determining the existence of string Intersections
Problem:
Given 2 strings, consider all the substrings within them
of length len. Len will be 1 or more.
Returns true if there are any such substrings which appear in both strings.
Compute ...
1
vote
1answer
75 views
Getting key-value from Object in Java
This takes a collection of Objects from JavaScript and puts them into a Java project. How can I improve this code? What's the best solution?
...
4
votes
2answers
162 views
Map String to list of string
Input: String : Title; List Tags
Problem statement:
Need to map title to tags, e.g. title is "china man japan beijing bell" and tags are ...
4
votes
1answer
113 views
Follow-up 2 to Morse Code String
This is my second follow-up. Major changes made:
Use a Map instead of an enum for the Morse Characters
Added ...
8
votes
3answers
254 views
Recursive Insertion in Hash Table (Linear Probing)
I was practicing implementing a hash function. I tried to use linear probing to insert in hash table. The insertion is working alright but I am not satisfied with the recursion. It doesn't feel like ...
4
votes
0answers
53 views
Finding Facebook Friends on app, and not on app
This code gets all of a user's Facebook friends who use our app and returns a dictionary with keys that are their id's in our database and values that are a default connection level.
The code should ...
0
votes
2answers
99 views
Split a Map into sublists
I may get a Map of many many items that needs to be requested to an API.
In order to improve performance, I thought about splitting that list into smaller ...
0
votes
4answers
99 views
Merge two dict in separate list by id
I have following data structure
>>> a = [{'id': 1, 'name': 'a'}, {'id': 2, 'name': 'b'}]
>>> b = [{'id': 1, 'age': 12}, {'id': 2, 'age': 21}]
I ...
4
votes
1answer
59 views
Mapping yielding lots of warnings in use
Recently, I wrote a C header file that defines a new type called HashMap that allows for the storage of key/value pairs.
I am just learning about the wonders of ...
6
votes
2answers
302 views
HashTable implementation
I have been trying to implement the Hash Table function in Java and here is what I came up with. I would just like to get an opinion on this work. Would there be a better way or any improvement to ...
5
votes
2answers
119 views
Hash Binary Tree Map
I made a map based on a binary tree ordered by hashcodes, with collisions fixed with equals(). Are there any improvements I could make?
...
5
votes
1answer
197 views
Regex matching keys in a Dictionary
I have extended this class http://wiki.unity3d.com/index.php/CSharpMessenger_Extended to accept strings containing wildcards as eventTypes, therefore I am able to ...
1
vote
1answer
57 views
Spatial hash triangles from multiple assets
I am implementing the spatial hashing algorithm described in Optimized Spatial Hashing for Collision Detection of Deformable Objects with a few adjustments, the largest one being that each bucket in ...
3
votes
0answers
40 views
Weeding out triangles for triangle-triangle collision detection using a spatial hash
I am implementing a multi-phase collision detection system whose final collision check is checking the triangles of one shape against those of another. As the number of triangle-triangle comparisons ...
3
votes
1answer
54 views
Finding average word length in a given year
I have written a function which takes the year in question and words as a data which is a dictionary that maps words to the list of year/count. Now I am wondering how I can improve the code that I ...
10
votes
4answers
550 views
Strategy pattern - design hash table
My programming skill has gotten rusty, so I would like to elicit constructive criticism that can make me write code better. I know the standard design is to use templates, and even obtain the hash ...
2
votes
2answers
479 views
Swift complexities with Dictionary
I have been trying to learn the various aspects of the languages I know so far to do the Daily Challenges in reddit (/r/DailyProgrammer). The one which I am working on just now asks for an ...
1
vote
1answer
195 views
Flattening a HashMap of (String → ArrayList) to an ArrayList
I have one HashMap<String, ArrayList<String>> and I want to concatenate a key with every item in its ArrayList.
...
-1
votes
2answers
91 views
Sorting array with respect to two properties
I'm sorting with respect to Width and Length. However, Width has the significance ...
5
votes
1answer
78 views
Dictionary Key look up with variable length inputs
I am decoding GS1 barcodes and need to match up application identifiers with relevant data about them.
...
4
votes
2answers
101 views
Convert Object Keys according to Table/Map object
I have implemented a recursive function that converts an object's keys according to another lookup table/map. You are able to convert back and forth using the 3rd ...
2
votes
2answers
92 views
Make a dict class from scratch in Python
Here's the API my teacher assigned:
and here is what I came up with:
...
5
votes
3answers
288 views
Map with different types for values
I am trying to implements a map (that can work as a cache) that has strings as keys and values of different types. In my real case once set the key/values in the map will not change.
I used these ...
5
votes
2answers
158 views
Chained hash table implementation
While reading a data structure book, I have implemented a chained hash table. I want to share the code with you and get your opinion about it.
chained_hash_table.h
...
4
votes
2answers
103 views
Fetch plist file
I have a plist file with many nested dictionaries inside of it, and I wanna fetch them all to my code. Isn't there any more efficient way to do that than nested for-loops?
...
