Questions tagged [hash-map]
A data structure that uses a hash function to map identifying values, known as keys, to their associated values
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Return whether the cards can be rearranged
I solved this question on LeetCode.com:
Alice has a hand of cards, given as an array of integers. Now she wants to rearrange the cards into groups so that each group is size W, and consists of W ...
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What is the best implementation of a ignore case dictionary In C#
Imagine we have a custom dictionary class which is derived from Dictionary<string, object>. Dictionary is case-insensitive about keys and elements arrange is ...
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C Hash table implementation
I have written a pretty simple hash table in C. It uses a prime modulus, linear probing, open addressing, and robin hood hashing.
The program can also be found on GitHub.
For clarification, ...
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Replacing all keys found in a dictionary for its value in a list
I have a file that is written DOS format and I need to replace some characters into others. I created a dictionary for that purposes, and now I have to read everyline from my stream and replace my ...
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Unscramble words faster in Python
So I'm currently using python to unscramble words that are retrieved from an OCR program, and checked in the 'dictionary'.
The current code I am using to unscramble words is this:
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Sorting through two dictionaries [closed]
What my code try to do here is to sort items trough 2 dictionaries. If they are similar or the same, I create a new list to append them.
The test file is relatively big, around 2000 data each ...
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Open-addressed C hashmap
I implemented an open-addressed, double-hashed hashmap in C, now looking for some advice on improving it. Thank you.
hashmap.h:
...
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Implement hash table using linear congruential probing in python
I have just read the Chapter 5 of Data Structures and Algorithms with Python. The authors implemented hash sets using linear probing. However, linear probing may result in lots of clustering. So I ...
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HashMap Implementation (dictionary) in Python
I attempted making a hashmap in python, and it was harder, due to some limitations but this is my version of dictionaries in python. Are there any way to simplify or do the same thing in less code ...
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Best way of converting a dynamic number of list items into variables in Python [closed]
I have a simple scrapy spider that crawls a page and returns H1 on the pages. Since, each page is unique, one cannot know how many h1's will be on the page. Since the scrapy spider returns a list, I ...
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Hash table in Java with arrays and linear probing
I did some manual tests by instantiating the class and it seems to be working okay. I wanted some feedback on the following:
Is the code well structured? I notice I have a lot of redundancy. The ...
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C# code for minimizing the sum of an array by dividing it's elements (repetition allowed) by 2 for k times
The assumption is that k is quite large as compared to no. of elements in the array and division by 2 returns ceiling of the result.
Request for your review and suggestions for further improvements ...
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regex on a log file utilizing stacks and queue's in Java
This would be for a MUD client, which has elements of a sort of telnet bot.
Here, there's ...
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Is this locked use of a Java HashMap thread safe?
I am trying to improve the performance of one of my project's methods, which obtains the command line of a process using WMI. A summary of key points:
The method is on an object representing a ...
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2
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Best approach for converting list of nested dictionaries to a single dictionary with aggregate functions
I've looked through a lot of solutions on this topic, but I have been unable to adapt my case to a performant one. Suppose I have a list of dictionaries stored as:
...
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2
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Increment values in a dictionary
In my continued venture to teach myself C# I came across an exercise using Dictionary. I created a class that has a method. In that method it creates a dictionary with keys/values. A string is ...
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Simplifying decision tree when working with map which has two keys and value as a slice
Can this logic not be simplified more, the code works, but it has become too much of a spaghetti. The requirements are that there should always be one connection if possible in ...
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Is this an optimal implementation for the knapsack algorithm?
I have implemented a solution for the knapsack problem while breaking an item is allowed. I've used the dictionary data structure where I used weight as a key and value per weight as a value. After ...
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Dictionary or custom Collection
I have a list of rule names coming from .xml file. These rule names needs to be validated against rule names in database (Validator.cs). If valid, then ...
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LeetCode: Divide Array in Sets of K Consecutive Numbers C#
https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers/
Given an array of integers nums and a positive integer k, find whether
it's possible to divide this array into sets of ...
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Finding out the indices of common elements in two array lists having duplicate elements
I have two lists which are also having some duplicate elements , i am converting this list to map as key value pair with element index as the value for the key - element
List 1 : [1, 2, 3, 4, 5, 6, ...
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Map of objects sharing characteristics [closed]
What I'm trying to achieve
From a list of lists of elements (one element can be in multiple lists, but only once in each list), I want to generate a map whose keys are each elements and the values ...
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Convert dict to array in Python [closed]
I have a dictionary that looks like this:
Counter({(1, 9): 3, (4, 2): 2, (3, 0): 1, (5, 4): 1})
I would like to convert it to an array that would look like this:
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Implementing a rectangle class
First I've to indicate that this is my homework.
An example of a given input is:
s1 = {'p1': (x1, y1), 'p2': (x2, y2)}
where all names and coordinations are ...
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Merging two dictionaries together whilst adding keys but multiplying values
I have two dictionaries and a merged dictionary:
dict1 = {-3: 0.3, -2: 0.1, 1: 0.8}
dict2 = {0: 0.3, 1: 0.5, -1: 0.7}
dict_merged = {}
I have code that basically ...
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Iterating lists and updating dictionary for corresponding match logic improvement
I have two lists:
Users - [<UserObject1>, <UserObject2>, ...]
Contributions - [...
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Takes json input and builds dynamic json output based on values in input: Looking for a better way to accomplish this
I have this specific scenario where I'm going to get a JSON that could have multiple Objects. From the Multiple Objects I will create a new Json that can have nested arrays growing by n amount ...
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1
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599
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Premier League data scraper
I have started a project where I am scraping JSON-data from an API. How the scraping is done right now is done in a very repetitive way where the keys of interest are specified and scraped. The data-...
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Pythonic way to cast a dictionary into a pd.DataFrame with two columns?
I have a dictionary where for each key, a single value is stored. Say
import pandas as pd
dd = {'Alice': 40,
'Bob': 50,
'Charlie': 35}
Now, I want to ...
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Better way to iterate through a dictionary and comparing its keys with itself
I have a dictionary with author names as keys and values of None. I want to use fuzzywuzzy ...
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get better performance [closed]
I have this code that works, but I'm sure that it can be done better, any suggestions?
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Updating a huge hashmap from a resultset
I am using Java 7
Problem: I need to retrieve records from a database table based on a condition, orig_setting = 1. This query could return ~1000 records. Parameters from 1-7 of the Params object are ...
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1
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Comparing dictionary values from list [closed]
I'm writing some Python code that will handle huge datasets.
On a small scale, this snippet works fine, but as the datasets become bigger it grinds my script to a halt (I know it is this part as I ...
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SHA256 javascript implementation
I implemented a sha256 hash function for javascript just for a practice and I want to know if my code needs more improvement. Please tell me which to simplify if there's any. Thanks.
Here is my code:
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Minimum amount of spaces inserted in a given string, such that it gets composed only of elements from a given list
The Challenge
Given a big string and a list of smaller strings, find the minimum amount of spaces that must be inserted between characters of the string in such way that it becomes composed only of ...
2
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1
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Print a word with numbers substituted for characters
I wrote the following Python program to take 1 word from the user and return certain characters replaced by numbers. Given a dictionary, the program should print all possible combinations of the same ...
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Create a 2 way mapping to allow you to stringify enums or map one enum to another
I've created a class that creates key->value pairs but also value->key pairs - i.e. a reversible hash-map. This is because I want to be able to switch between corresponding members of 2 enums ...
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Python Hash Table implemented using lists
I implemented a Python Hash Table using only lists.
Here is my implementation:
...
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2
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193
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Bi Directional Dictionary
I wrote a class that extends the dict class to provide indexing like functionality, so I can find which key(s) map to a given value in the dict. It's pretty bare ...
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1
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To convert all the class properties to IDictionary<string, dynamic>
I have the requirement to return the result of my ViewModel as a Dictionary of KeyValue pairs. My view model comprises of multiple classes and can have null values in properties. I need to return only ...
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Add items to Dictionary from another dictionary on cell value change
I have created a very simple Class Module and a Dictionary to store original values when the workbook is opened as part of this project ive been working on. When the workbook opens I call a test to ...
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Removing duplicate hashes in an array while keeping count of the times the hash was present
I have an array of hashes (price_params['items']) where each item has a key called quantity what I'm trying to do is to clean ...
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Creating an affinity-matrix between protein and RNA sequences
I wrote an algorithm that analyzes protein-RNA interactions and I found that the following function is the bottleneck that causes performance issues:
...
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Normalizing mixed format nested dictionary with delimiter separated keys
I recently worked with some pickle files which had a really strange format where the keys are sometimes delimiter separated with colons and placed in the same depth but also mixed with ordinary key ...
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HashMap in Python
This is a HashMap implementation written in Python. All the methods are based on the java implementation of a HashMap. Any and ...
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HashSet without collision
I have written a custom HashSet and though it isn't completed yet (this code does not consider test cases with collisions), I would like to know if there is anything I can improve in areas of clean ...
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2
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Check if dictionary keys are declared, if not leave them as true
I've tried with:
dictionary.TryGetValue("MoreDetails", out bool MoreDetails);
but if the key is not present it defaults to false, and I need it to default to ...
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2
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1
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Dictionary function for R
I'm new to R and have created a dictionary function. A user will input a phrase into a text field and the server will read it and see if there's a match in a back-end data table and if so, output the ...
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Extraction of value from a dict-tree, given a path of arbitrary length
Problem: We read a complex json-file which grants us a tree in terms of a python "dict of dicts". We're then requested to retrieve a specific path from the tree, represented by a list of elements. The ...
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