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.
6
votes
2answers
172 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 ...
0
votes
0answers
25 views
Obtaining only the values that are inside an interval given a list [closed]
I'm trying to add the element a into a list A in the case that there is only one value b in the list B that is inside the interval [a * 0.999999 , a * 1.000001]. I have around 180.000 values to treat ...
4
votes
2answers
206 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:
...
3
votes
1answer
44 views
2
votes
3answers
38 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 ...
2
votes
2answers
65 views
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 ...
3
votes
3answers
99 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:
...
2
votes
1answer
34 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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3
votes
2answers
87 views
0
votes
2answers
42 views
1
vote
2answers
46 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 ...
2
votes
2answers
75 views
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 ...
2
votes
2answers
83 views
Dictionary foreach loop with multiple occurences
A little look on what are Dictionaries:
dictWordCounter<string, int>
dictWordPercent<string, double>
topTwentySeven<string, double>
...
6
votes
2answers
98 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 ...
1
vote
2answers
64 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 ...
2
votes
0answers
100 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 ...
4
votes
1answer
83 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 ...
4
votes
1answer
87 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 ...
3
votes
2answers
56 views
Forming a dictionary where all values are only conditionally set
I have lots of dictionary keys with conditional values, ternary in this case:
...
8
votes
2answers
797 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. ...
1
vote
2answers
59 views
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.
...
1
vote
1answer
59 views
Reading two csv files as dictionaries with differing key definitions
My script reads two .csv files and generates one dictionary per .csv file.
...
1
vote
2answers
253 views
Check for null/empty in dictionary
I am doing the following about 10 times with other strings, so the code is duplicated. How can I refactor this?
queryWhere is a ...
1
vote
0answers
59 views
Map operation to update data | Hazelcast IMap returns clone object
I have a nested hazelcast distributed map:
Map<CountryId, Map<CityCode, Map<data_key,data_value>>>
where "data_key" is "population", ...
4
votes
1answer
81 views
String find and replace method optimization
I am trying to find a specific header string from different Maps (LEDES1998Bheaders, LEDES98BIheaders and ...
1
vote
1answer
30 views
Reordering OrderedDict
Goal: create a new OrderedDict instance's keys in such way that keys in the specified order list appear first. If some keys in order list are not present in ...
1
vote
0answers
153 views
A dictionary that allows multiple keys for one value
I'm trying to learn to program on my own with the help of books and the Internet and thought I'd start a project (a sub-project for a project).
I want to build a dictionary that allows multiple keys ...
8
votes
0answers
151 views
Making a generic NSMapTable replacement written in Swift thread-safe
This is a follow-up to this question. While discussing some details about the code I posted there, I came upon a problem with thread-safety. After searching and trying different things, I reached a ...
6
votes
2answers
150 views
Generic NSMapTable replacement written in Swift
This is my attempt at writing a generic NSMapTable with weak keys and strong values (after your feedback I'll be trying to write Strong-Key/Weak-Value and ...
4
votes
2answers
118 views
Convert a list of dictionaries to a dictionary of dictionaries
I need to convert a list of dictionaries to a dictionary of dictionaries, with a particular item as the new key.
This is the way I'm currently doing it:
...
3
votes
2answers
102 views
Simple string hashing algorithm implementation
I thought of a simple way to hash a string. By taking the ASCII decimal value of each character, multiplying it by 10, and adding all of the values computed together for each character in a string. Is ...
2
votes
1answer
67 views
Haskell requires more memory than Python when I read map from file. Why?
I have this simple code in Python:
...
3
votes
2answers
91 views
“Invert” a JavaScript object hash whose values are arrays to produce a new object hash with keys as the elements of those original value vectors
Background
lodash and underscore have an invert function that takes an object hash and converts it to a new one, which has keys as the input object's values and ...
0
votes
1answer
56 views
log(n) “sort by value” Map<K, V>?
I've read so much arguing about "sort by value maps". Well, I wrote the following log(n) sort by value Map . And, by the way, a real Map , does not allow duplicate keys. Many of the maps I googled ...
0
votes
1answer
20 views
Search strings within a list from strings within a dictionary with the least complexity
I have the following input:
newValue = [['men', 'John Doe,Chris perry'], ['women', 'Mary,Anne,Lita']] - list within list
...
3
votes
2answers
277 views
Data Persistence
I was wondering if I could get some feedback on the library I created to persist data online.
JitterPushDemo.java
...
3
votes
1answer
76 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
17 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
236 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 ...
13
votes
1answer
149 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
153 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 ...
3
votes
2answers
131 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
79 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
238 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
68 views
LRU Cache Design using LinkedHashMap
This is a follow-on qestion from: LRU cache design
Revised Implementation
...
5
votes
2answers
115 views
6
votes
0answers
59 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
291 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
