lookup

I have a 123MB big int array, and it is basically used like this: private static int[] data = new int[32487834]; static int eval(int[] c) { int p = data[c[0]]; p = data[p + c[1]]; p = data[p + c[2]]; p = data[p + c[3]]; p = data[p + c[4]]; p = data[p + c[5]]; return data[p + c[6]]; } eval() is called a lot (~50B times) with different c and I would like to know if (and how) I could speed it up. I already use a unsafe function with an fixed array that makes use of all the CPUs. It's a C# port of the TwoPlusTwo 7 card evaluator by RayW . The C++ version is insignificantly faster. Can the GPU be

In R, I have, for example: > foo <- list(a=1,b=2,c=3) If I type foo , I get: $a [1] 1 $b [1] 2 $c [1] 3 How can I look through foo to get a list of "keys" only? In this case, (a, b, c). An R list can have named elements and so function as a dictionary structure. You can just do: > names(foo) [1] "a" "b" "c" If you are looking for a dictionary structure you might also consider using the hash packages which provides a Python and Perl like dictionary/hash with the expected functions such as keys , so you can say: keys(hash) In terms of performance a list serves as a better dictionary than a hash

#!/bin/bash # Command line look up using Google's define feature - command line dictionary echo "Type in your word:" read word /usr/bin/curl -s -A 'Mozilla/4.0' 'http://www.google.com/search?q=define%3A+'$word \ | html2text -ascii -nobs -style compact -width 500 | grep "*" Dumps a whole series of definitions from google.com an example is below: Type in your word: world * universe: everything that exists anywhere; "they study the evolution of the universe"; "the biggest tree in existence" * people in general; especially a distinctive group of people with some shared interest; "the Western world

This question already has answers here : Javascript ES6 computational/time complexity of collections (2 answers) I have seen in an answer that the Set.has() method is O(1) and Array.indexOf() is O(n). var a = [1, 2, 3, 4, 5]; a.indexOf(5); s = new Set(a); s.has(5); //Is this O(1)? Is Set.has() really O(1) ? If one read the specification of has() , there is an algorithm describing it: Algorithm for Set.prototype.has(value) : The following steps are taken: Let S be the this value. If Type(S) is not Object, throw a TypeError exception. If S does not have a [[SetData]] internal slot, throw a

The title says it all. How come if a document does not result in any matching outer document according to its matching field, then how come it's not included in the pipeline's result set? I'm testing out the new aggregators in Mongo 3.2 and I've gone so far as to perform a nested array lookup by first unwinding, and then grouping the documents back up. All I have left is to have the results include all local documents that didn't meet the $lookup criteria, which is what I thought was the standard definition of "left outer join". Here's the query: db.users.aggregate([ { $unwind: "$profile",

How do I perform a reverse DNS lookup, that is how do I resolve an IP address to its DNS hostname in Perl? gethostbyaddr and similar calls. See http://perldoc.perl.org/functions/gethostbyaddr.html If you need more detailed DNS info use the Net::DNS module, here is an example: use Net::DNS; my $res = Net::DNS::Resolver->new; # create the reverse lookup DNS name (note that the octets in the IP address need to be reversed). my $IP = "209.85.173.103"; my $target_IP = join('.', reverse split(/\./, $IP)).".in-addr.arpa"; my $query = $res->query("$target_IP", "PTR"); if ($query) { foreach my $rr (

I'm just learning DDD (Eric Evans book is open in front of me) and I've come across a problem that I can't find an answer for. What do you do in DDD when you're just trying to get a simple list of lookup records? Ex. EmployeeID: 123 EmployeeName: John Doe State: Alaska (drop-down) County: Wasilla (drop-down -- will be filtered based on state). For example, let's say that you have an Employee domain object, an IEmployeeRepository interface and an EmployeeRepository class. This will be used by a UI to show a list of employees and individual details. In the UI, you want to use a drop-down for the

I want to populate a cell according to the range of another cell. Like if the independent cell has the value between 12 to 16 then the dependent cell will be populated as -2 and if the independent cell has a value between 16 to 20 then -1 and if 20 - 24 then N and so on: Sample Is there any formula or how otherwise can I do it? Assuming 16 is "between" 16-20 rather than "between" 12-16 and that for N it is the text of the OP that counts rather than the image: =LOOKUP(A1,{12,16,20,24},{-2,-1,"N"}) Negative values, zero, numbers less than 12 and positive or greater than 24, blanks and text would