The **equals** in Set interface.
As we know two Set instances are equal iff they contain the same elements, BUT is it possible to have the same element in two different sets (Set interface can not contain duplicate element)? ...
sets
What does this statement mean?
I am a beginner in Java and do not understand what if(!s.add(a)) means in this code excerpt: Set<String> s = new HashSet<String>(); for(String a:args) { if(!s.add(a)) System.out.println("Duplicate detected:"+a); } ...
Help me fix this C++ std::set comparator
This is the code: struct comp { bool operator()(Reputation *one, Reputation *two) { if (one->Amount < 0 && two->Amount >= 0) return false; if (one->Amount >= 0 && two->Amount < 0) return true; if (one->Amount >= 0) return one->Amount <= two->Amount; else return one->Amount >= two->Amount; } }; And this is the p...
Quick jQuery question: What's the way to get all elements of a queried set EXCEPT the first?
I forget offhand. ...
std::set with user defined type, how to ensure no duplicates.
Hello. So I have an std::set which needs to keep specific ordering as well as not allowing duplicates of a user defined (by me) type. Now I can get the order to work correctly by overloading the '<' operator in my type. However, the set does not appropriately detect duplicates, and to be honest I'm not entirely sure how it does this inte...
Intersection of result sets: Existing API?
Suppose I run k-many sub-queries against e.g. tables in a database(s), and the results from each query share a common field e.g. a string, or uuid value, which shares meaning across these tables. Assuming I can have the queries returned sorted, are there API's which exists in languages already which allow me to find the intersection of ...
slow implementation of Union and Intersection
I'm trying to find a better way to implement these methods, as over very large sets they take a very long time, any ideas? import java.util.HashMap; import java.util.HashSet; public class Multiset<E> extends HashSet<E> { private static final long serialVersionUID = -9013417064272046980L; private HashMap<E, Integer> multiplicit...
Powershell, kind of set intersection built-in?
For some game where one would need to find anagrams from a bunch of loose letters I ended up implementing a permutation algorithm to find all possible anagrams and filter those if needed for known letter positions (-match is great, by the way). But for longer words this proved very much error-prone, as skimming a large list of gibberish ...
Flag itersection of two lists using LINQ
I have two lists, one which is a subset of the other. List 1: A, B, C, D, E List 2: B, D, E I'd like to end up with a single collection of the superset with items contained in the subset flagged. This seems to be the sort of thing LINQ could do, but I'm not sure of the syntax. Result: A, false B, true C, false ...
An unbounded set of hashes based on bounded sets of hashes based on paths
Suppose there is a tree, for argument's sake an XML tree. And you want a complete set of root to node paths, however you want to divide that set into groups of i, where i is user specified. So for example a html document: /html /html/head /html/head/title /html/head/title/[text] /html/body /html/body/[text] becomes for example...
Is there a set type in .NET 2.0?
Possible Duplicate: Is there a Set data structure in .Net? Duplicate: this is a duplicate of "Is there a “Set” data structure in .Net?". Please close it as a duplicate and address any further answers to the earlier question. Is there a generic collection analogous to the STL set<T> template in the .NET framework? If not, how w...
Find unique elements in tuples in a python list
Is there a better way to do this in python, or rather: Is this a good way to do it? x = ('a', 'b', 'c') y = ('d', 'e', 'f') z = ('g', 'e', 'i') l = [x, y, z] s = set([e for (_, e, _) in l]) I looks somewhat ugly but does what i need without writing a complex "get_unique_elements_from_tuple_list" function... ;) edit: expected value ...
LINQ to SQL - Struggling with query
I have a table with server names and logins. I need to retrieve the logins that are common across a group of servers. Given the following data: ServerName Login ------------------------------- Server1 User1 Server2 User1 Server2 User2 I would pass in Server1,Server2 and get back only User1 as User2 is not associ...
Comparison Algorithm.
I have 2 arrays (A and B) that contain similar data with some differences. I would like to return an array of objects that are only in A and another array of objects that are only in B. So far I have been thinking: Brute force with some optimizations (this is trivial) Sort the arrays and use a binary search. What are my other option...
Superset Search
I'm looking for an algorithm to solve the following in a reasonable amount of time. Given a set of sets, find all such sets that are subsets of a given set. For example, if you have a set of search terms like ["stack overflow", "foo bar", ...], then given a document D, find all search terms whose words all appear in D. I have found tw...
Objective C: How do I make an NSMutableSet of NSMutableDictionaries, and have them be unique based on one of the dictionary values?
The reason I'm asking this is because right now I use an NSMutableSet of integers and a corresponding NSMutableArray to store the rest of the data, but I think I'm not using the language right. Here's my code: In the init function: self.markerList = [[NSMutableArray alloc] init]; self.markerIdSet = [[NSMutableSet alloc] init]; And t...
What's a good mathematical sets implementation in JavaScript?
Where is a good mathematical sets implementation for JavaScript? It should include efficient implementations of intersection, union, complement, and (for bonus points) the Cartesian product. No, it's not homework. I got a yubikey, it is a USB keyboard that types a sequence chosen from 16 keycodes to type a 128-bit one time password (otp...
Hibernate WrongClassException / Sets / Discriminators?
Hi, The problem looks like this: A Product table. 3 joined-subclasses: DVD, CD, Book. A Role table (composite id: NAME, ROLE, PRODUCT), and subclasses by discriminator column ROLE: actor, director, artist, author, etc.. which are mapped to Actor, Director, Artist, Author java classes; (pretty usual I guess) ... A Book has authors, a C...
Mysql Query Exclude a certain entry
Hi all, I'm trying to SELECT entries of a certain type, name, EXCLUDING entries with the same name in a particular id. The last part is the tricky part that I can't get my head around. SELECT name FROM table WHERE type = $type AND (name is not contained in an entry with id). I want the result to be the set of all names that ARE...
Where can I find good mimetype icons?
I would like to find good icons for mimetypes to use in my (filetype, mimetype) -> icon website : http://stdicon.com/ I currently have apache crystal gnome silk tango but if there are other free high quality sets out there I would like to include those as well. ...