Say you have a linked list structure in Java. It’s made up of Nodes: class Node { Node next; // some user data } and each Node points to the next node, except for the last Node, which has null for next. Say there is a possibility that the list can contain a loop – … Read more
This question’s answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. I have a data structure that represents a directed graph, and I want to render that dynamically on an HTML page. These graphs will usually be just a few nodes, maybe ten … Read more
I’m looking for an explanation of how a hash table works – in plain English for a simpleton like me! For example, I know it takes the key, calculates the hash (I am looking for an explanation how) and then performs some kind of modulo to work out where it lies in the array where … Read more
Is there any standard Java library class to represent a tree in Java? Specifically I need to represent the following: The sub-tree at any node can have an arbitrary number of children Each node (after the root) and it’s children will have string value I need to get all the children (some sort of list … Read more
I want to check whether the “user” key is present or not in the session hash. How can I do this? Note that I don’t want to check whether the key’s value is nil or not. I just want to check whether the “user” key is present. 8 s 8 Hash‘s key? method tells you … Read more
Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. There are some data structures around that are really useful but are unknown to most programmers. Which ones are they? Everybody knows about linked lists, binary trees, and hashes, … Read more
What is the best way to implement a Stack and a Queue in JavaScript? I’m looking to do the shunting-yard algorithm and I’m going to need these data-structures. 29 s 29 var stack = []; stack.push(2); // stack is now [2] stack.push(5); // stack is now [2, 5] var i = stack.pop(); // stack is … Read more
What’s the simplest, library-free code for implementing array intersections in javascript? I want to write intersection([1,2,3], [2,3,4,5]) and get [2, 3] 37 s 37
I feel a bit thick at this point. I’ve spent days trying to fully wrap my head around suffix tree construction, but because I don’t have a mathematical background, many of the explanations elude me as they start to make excessive use of mathematical symbology. The closest to a good explanation that I’ve found is … Read more
In most programming languages, dictionaries are preferred over hashtables. What are the reasons behind that? 1 19 For what it’s worth, a Dictionary is (conceptually) a hash table. If you meant “why do we use the Dictionary<TKey, TValue> class instead of the Hashtable class?”, then it’s an easy answer: Dictionary<TKey, TValue> is a generic type, … Read more
