I’ve used it for an in-memory log with a restricted size. For example, the application would write log entries while processing user requests. Whenever an exception occurred (that would be disruptive to the processing) the log records currently in memory would be dumped along with it. The benefit of a circular buffer is, that you … Read more
What is happening here is, if you have an array of n elements, then the segment tree will have a leaf node for each of these n entries. Thus, we have (n) leaf nodes, and also (n-1) internal nodes. Total number of nodes= n + (n-1) = 2n-1 Now, we know its a full binary … Read more
You don’t need to re-add the ArrayList back to your Map. If the ArrayList already exists then just add your value to it. An improved implementation might look like: Map<String, Collection<String>> map = new HashMap<String, Collection<String>>(); while processing each line: String user = user field from line String value = value field from line Collection<String> … Read more
In your array implementation, your Query 1.1 seems to be the best way to do things. The only other way to remove a random element would be to move everything up to fill its spot. So if you had [1,2,3,4,5] and you removed 2, your code would move items 3, 4, and 5 up and … Read more
A Haskell program’s structure is surprisingly simple. You have a main function which does IO, and that’s about it. So the basics: module Main where addition a b = a + b main :: IO () main = do let z = addition 5 3 putStrLn $ “The result is: ” ++ show z Now … Read more
The only reason is to avoid clustering of values into a small number of buckets (yes, distribution). A more even distributed hashtable will perform more consistently. from http://srinvis.blogspot.com/2006/07/hash-table-lengths-and-prime-numbers.html If suppose your hashCode function results in the following hashCodes among others {x , 2x, 3x, 4x, 5x, 6x…}, then all these are going to be clustered … Read more
You could read up on Java Trie or look at trie.
My favorite way to do this kind of things is like this: input.map { case (k,v) => (k.getBytes, v) }(collection.breakOut): List[(Array[Byte], List[Int])] With this syntax, you are passing to map the builder it needs to reconstruct the resulting collection. (Actually, not a builder, but a builder factory. Read more about Scala’s CanBuildFroms if you are … Read more
I spotted the following solution somewhere on the web and I’m using it in my projects: template <class T, class S, class C> S& Container(priority_queue<T, S, C>& q) { struct HackedQueue : private priority_queue<T, S, C> { static S& Container(priority_queue<T, S, C>& q) { return q.*&HackedQueue::c; } }; return HackedQueue::Container(q); } int main() { priority_queue<SomeClass> … Read more
JObject jsonObject=JObject.Parse(theJsonString); IEnumerable<JToken> jTokens = jsonObject.Descendants().Where(p => !p.HasValues); Dictionary<string, string> results = jTokens.Aggregate(new Dictionary<string, string>(), (properties, jToken) => { properties.Add(jToken.Path, jToken.ToString()); return properties; }); I had the same requirement of flattening a nested json structure to a dictionary object. Found the solution here.