Questions tagged [hashtable]
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23 questions
0 votes
1 answer
226 views
Hash Indexes vs LSM trees with SSTables
I was reading Designing-Data Intensive Applications, and I am confused about the usage of LSM trees with SSTables. The author talks about Hash Indexes and log files (written as segments which are ...
- 254
4 votes
4 answers
615 views
The fastest method for removing duplicate files safety?
I have a huge amount of files (mostly documents like pdf ~80-90%, but also images, videos, webpages, audio etc.), somewhere around 3.8 millions of files which occupies ~7.8Tb of hard drive space on a ...
- 149
0 votes
0 answers
460 views
CRC32C as hash for hashmap
So I've been looking around to find a suitable hash function for a hashmap. Currently the best one I've found was from xxhash and maybe murmur after that, but they excluded CRC32C which can be ...
- 9
-1 votes
1 answer
270 views
A data structure / algorithm to combine search tree and hash table?
I have a two dimensional data with one dimension is ordered and another one is categorical, for example, country and city_age: country age city Italy 2773 Rome Germany 784 Berlin USA 397 New York ...
- 157
1 vote
2 answers
860 views
Can you create a hash table made of binary trees?
For instance, if you have a hash table with the array of buckets 26 nodes long, one for each letter of the alphabet. You use that to keep track of names. So when a name "Jed" is added to the ...
- 19
0 votes
1 answer
137 views
how to store the data for function f(time,length)
I have a function which has discrete time step ,discrete length from origin . These two give height of the function. For example at time 1.2sec , and length 5.5cm from origin height is 10cm. The step ...
- 19
0 votes
1 answer
3k views
What is the space complexity of a Python dictionary?
If python dictionaries are essentially hash tables and the length of hashes used in the python dictionary implementation is 32 bits, that would mean that regardless of the number of key-value pairs ...
- 127
2 votes
2 answers
1k views
Load factor and prime number for hashing in HashTable
I am trying to design a HashTable from scratch. I am starting with an initial bucket size of 11 and trying to maintain a load factor 0.75. Java documentation mentions that whenever the number of ...
- 133
8 votes
5 answers
9k views
Implementing a hash table with true concurrency
This was recently a question I was asked in a screening and it got me thinking. I never totally settled on how the conversation ended, and I did some digging. None of the answers I saw seemed ...
- 235
0 votes
0 answers
131 views
Searching/Hashing Wikipedia - at each position for keys 1..31 long, the fastest way?
A C coder here. My wish is to find the best way to search words and phrases within the ever-growing English Wikipedia XML dump. As a first layer/step, hashing is the answer, yes? The problem is that ...
- 17
1 vote
1 answer
98 views
Library with different runtime behaviour based on usage history (design question) [closed]
I want to design a hash table library that keeps usage statistics and based on how it is used will use different implementations at runtime. For example use a certain implementation for small size ...
- 187
3 votes
1 answer
111 views
java hashtable extending to support duplicates
I have to maintain an old application and have to extend some modules. There is an hashtable that is used for maintaining/holding some objects as representation of running (real) processes (don't see ...
- 149
0 votes
1 answer
554 views
Logic Behind a Basic Hash Table Hashing Algorithm
I am trying to write a Hash Table in Java based on some Princeton article about it. The most commonly used method for hashing integers is called modular hashing: we choose the array size M to be ...
- 179
4 votes
2 answers
6k views
How exactly indexing works in arrays?
I only know that index is faster but don't know why is it faster. Suppose I have an array int[] a = {2,3,6,7}. Then I will try to find the element at a[3] and the speed of this will be O(1). Why? How ...
- 151
3 votes
1 answer
1k views
Hash Table with iterators as the keys, is this poor design and can I do this better?
I'm developing a program where twice I've found the solution to a problem was to use hash tables with iterators as keys and some other arbitrary type as the value. I found my self using this pattern ...
- 1,347