I have two numpy arrays of integers, both of length several hundred million. Within each array values are unique, and each is initially unsorted. I would like the indices to each that yield their ...

I have a large collection of several million sets, C. The elements of my sets come from a universe of about 2000 possible elements. I need to know, for a given set, s, which set in C has the larges...

I have 4 lists a <- list(1,2,3,4) b <- list(5,6,7,8) c <- list(7,9,0) d <- list(12,14) I would like to know which of the lists have elements in common. In this example, lists b and c...

If I have a variable number of sets (let's call the number n), which have at most m elements each, what's the most efficient way to calculate the pairwise intersections for all pairs of sets? Note ...

I have been using the highly concise and intuitive C++ syntax for finding the intersection of two sorted vectors and putting the result in a third vector: vector<bar> a,b,c; //... std::set_i...

Currently I am stuck trying to find the intersection of three sets. Now these sets are really lists that I am converting into sets, and then trying to find the intersection of. Here's what I have ...

I am trying to use use std::set_intersection to find common elements between 2 completely different types of data structures that have a common binding 'name' field. I looked at the following ent...

Is there an algorithm that, given two sets, computes their intersection in linear time? I can run two for loops to check all pairs of elements, recording elements that I find in both of the sets. ...

I know that in PostgreSQL you can run a query like: SELECT (1 = ANY('{1,3,4,7}'::int[])) AS result to check if the right-hand array contains the element 1. I was wondering if there is an easy way ...

First of all, my purpose is to randomly get only one element in both known sets. So my original method is firstly intersect two sets. And then randomly pick up a element from the intersected set. B...

I would like to know if this is possible to solve using a lambda expression: List<Foo> listOne = service.GetListOne(); List<Foo> listTwo = service.GetListTwo(); List<Foo> result ...

I'm trying to use the Mongo aggregation framework to find where there are records that have different unique sets within the same document. An example will best explain this: Here is a document th...

I have come across some special purpose implementation of set operations, but nothing for the general case. What is the general case for performing set operations (specifically intersection, union,...

I haven't been able to find any satisfactory coverage of this topic all in one place, so I was wondering: What are the fastest set intersect, union, and disjoin algorithms? Are there any interestin...

Is there a method in java.util.Map or any util to perform an intersection on two maps? (To intersect two maps by the "keys") I am not able to find any. I can always implement my own intersection l...

I have a collection of std::set. I want to find the intersection of all the sets in this collection, in the fastest manner. The number of sets in the collection is typically very small (~5-10), and...

This is somewhat related to a question I asked not too long ago today. I am taking the intersection of two lists as follows: inter = set(NNSRCfile['datetimenew']).intersection(catdate) The two ...

So, there exists an easy way to calculate the intersection of two sets via set.intersection(). However, I have the following problem: class Person(Object): def __init__(self, name, age): self....

What is the complexity of the following code? set<int> S1, S2, ans; set_intersection(S1.begin(), S1.end(), S2.begin(), S2.end(), inserter(ans, ans.begin())) where S1 and S2 are some non_em...

I have a code snippet like this, to be compiled under VC++ 2010. std::set<int> s1; std::set<int> s2; std::set<int> res_set; std::set_intersection(s1.begin(), s1.end(), s2.beg...