I'm writing a program right now which produces four unsigned 32-bit integers as output from a certain function. I'm wanting to hash these four integers, so I can compare the output of this function to future outputs. I'm having trouble writing a decent hashing function though. When I originally wrote this code, I threw in a simple addit...
Consider a "person" stored in a hash. Two examples are: fred = {:person => {:name => "Fred", :spouse => "Wilma", :children => {:child => {:name => "Pebbles"}}}} slate = {:person => {:name => "Mr. Slate", :spouse => "Mrs. Slate"}} If the "person" doesn't have any children, the "chilren" element is not present. So, for Mr. Slate, we ca...
Ok, so I wanted to create a hash which has an empty hash as the default value. A bit weird, I know, but let's say that I thought it might be useful. So here's what I did: >> a = Hash.new({}) => {} >> a[:a][:b] = 5 => 5 >> a => {} >> a[:a] => {:b=>5} >> a.keys => [] >> a.size => 0 >> a[:a].size => 1 In other words, I don't see hash me...
Heya guys. I'd like to get the value after a hash in the URL of the current page and then be able to apply this in a new function... eg. The URL could be www.example.com/index.html#foo And I would like to use this in conjunction with the following piece of code $('ul#foo:first').show(); I'm kinda assuming/hoping there is some...
If I'm turning a ruby hash into a string of name-value pairs (to be used in HTTP params, for example), is this the best way? # Define the hash fields = {"a" => "foo", "b" => "bar"} # Turn it into the name-value string http_params = fields.map{|k,v| "#{k}=#{v}"}.join('&') I guess my question is: Is there an easier way to get to http_...
I have to pass two references as arguments to a subroutine (buildRanges) as hash key-value pairs as show below Example: @array = (“0A0”, “005”, “001”, “004”, “0BC”, “004”, “002”, “001”); @ranges = (); $numRanges = buildRanges(VALUES => \@array, REF_RANGES=>\@ranges); My question is 1. is the syntax for the sub-routine call above is...
I use GhostDoc for the XML-Documentation of my code, and it has a neat "auto-document"-function I use quite often, so now I used it on an enumeration and it came up with some strange hash-code I don't quite understand. What is it for? Looks sort of like this: {35A90EBF-F421-44A3-BE3A-47C72AFE47FE} ...
In my ASP.NET web app I'm hashing my user passwords with SHA512. Despite much SO'ing and Googling I'm unclear how I should be storing them in the database (SQL2005) - the code below shows the basics of how I'm creating the hash as a string and I'm currently inserting it into the database into a Char(88) column as that seems to be the le...
Is there a way to dynamically create arrays in Ruby? For example, let's say I wanted to loop through an array of books as input by a user: books = gets.chomp The user inputs: "The Great Gatsby, Crime and Punishment, Dracula, Fahrenheit 451, Pride and Prejudice, Sense and Sensibility, Slaughterhouse-Five, The Adventures of Huckleberry...
Ok, so I've been doing some experiments with hash tables and different collision resolution problems. I'm trying to figure out which is more efficient for doing finds, a hash table that uses separate chaining or quadratic probing for collision resolution. My results suggest that separate chaining is faster than quadratic probing even for...
If I want to use the hash function object provided in STL, which header file I should include on Linux? e.g. hash Hf; ...
Hey guys, I run a rather large site where my members add thousands of images every day. Obviously there is a lot of duplication and i was just wondering if during an upload of an image i can somehow generate a signature or a hash of an image so i can store it. And every time someone uploads the picture i would simply run a check if this ...
Hi In several hash table implementations I've seen the usage of heuristics like "transpose" or "move to front" for items in a bucket. What are the advantages of using such heuristics? I could't figure it out myself. Which other optimizations can be done at the hash table / bucket level, why, and under which circumstances? Optimizing...
I did a fair bit of looking around on the board before I posted here but I didn't see anything that captured what I was hoping to do. We receive a large number of inbound faxes (500+ pages/day) as separate documents (around 100+ documents/day). Quite often the sender (being a hospital) resends the same document a couple hours after the ...
Can you have hash tables or dicts in Lisp? I mean the data structure that is a collection of pairs (key, value) where values can be acceded using keys. ...
I need to get all of the values for a certain key in a hash. The hash looks like this: $bean = { Key1 => { Key4 => 4, Key5 => 9, Key6 => 10, }, Key2 => { Key7 => 5, Key8 => 9, }, }; I just need the values to Key4, Key5 and Ke...
Hello, I have a "Dictionary" data base and I want to return an element from a specific location. I saw that there is "ElementAt" function but I didnt manage to use it. Why doesnt something like that work? closeHash.ElementAt<State>(i); it tells me the following error: Error 3 'System.Collections.Generic.Dictionary' does not conta...
If I have a dictionary in Python, and I iterate through it once, and then again later, is the iteration order guaranteed to be preserved given that I didn't insert, delete, or update any items in the dictionary? (But I might have done look-ups). ...
Hi, i need to do a school project in C (I'm really don't know c++ as well). I need a data struct to index each word of about 34k documents, its a lot of words, and need to do some ranking about the words, i already did this project about 2 years ago (i'm pause in the school and back this year) and a i use a hash table of binary tree, bu...
It seems there's an implementation of HMAC in every language under the sun. (See below.) And the algorithm is quite straightforward: http://en.wikipedia.org/wiki/HMAC Has anyone implemented it in Mathematica? Here are pointers to implementations in other languages: http://docs.python.org/library/hmac.html http://php.net/manual/en/fu...