hashtable

问题 Hello I have a custom Hash that needs to be returned in an API. But currently I'm struggling to find a good way to do so. The following example will describe the problem. Lets say we have the following code: data = {name: "Jon", value: "13"} results = [] [1, 2, 3, 4, 5].each do |i| data[:id] = i results << data end # output # results = [{name: "Jon", value: "13", id: 5}, {name: "Jon", value: "13", id: 5}, {name: "Jon", value: "13", id: 5}, {name: "Jon", value: "13", id: 5}, {name: "Jon",

问题 We use a component implemented in a DLL. It is inherited from System.Windows.Forms.Control. We need to use it as keys in a .NET Hashtable object. As MSDN states, The objects used as keys by a Hashtable are required to override the Object.GetHashCode method (or the IHashCodeProvider interface) and the Object.Equals method (or the IComparer interface). But the control we are talking about does not have its own implementation of the GetHashCode method. The documentation for Object.GetHashCode

问题 I need to implement Zobrist hashing for a chess engine in Javascript and I'm wondering what is the best way of accomplishing this. Now, I'm not a computer scientist and never had formal algorithms and data structures classes so I'm sorry if I'm a bit off on this... From what I understand I need a 64 bit hashfunction to encode a position as lower than that originates too many collisions. Now in javascript I only have access to 32 bits numbers. Also there is an issue with how I implement the

问题 I want to implement my own hash table using chaining and linked list but I am having a hard time figuring out how to use the implementation in the main method. I need to read a comma separated values file with data and store the names as keys and the two floating points as a value. I know I need to use object oriented programming but I having a difficult time accessing my data using my implementation. Here is my code: public class LinkedListHash{ String key; String value; LinkedListHash next;

问题 Dear Stackoverflow community, I have looked everywhere but can't find the answer to this question. I am trying to access the factor lookup table that R uses when you change a string vector into a factor vector. I am not trying to convert a string to a factor but rather to get the lookup table underlying the factor variable and store it as a hash table for use elsewhere. I encountered the problem because I want to use this factor lookup table on a list of different length vectors, to convert

问题 I have this code which works well: static { myStore = PersistentStore.getPersistentObject(MY_LONG_KEY); myList = (Vector) myStore.getContents(); if (_storedStations == null) { myList = new Vector(4); // prepopulate with fake data myList.addElement(new MyItem("Eins")); myList.addElement(new MyItem("Zwei")); myList.addElement(new MyItem("Drei")); myList.addElement(new MyItem("Vier")); myStore.setContents(myList); } } class MyItem implements Persistable { ..... } probably because the

问题 I have a configuration.csv that holds a template data like this: | path | item | value | type | |------------|-------|--------|------| | some/path | item1 | value1 | ALL | | some/path | item2 | UPDATE | ALL | | other/path | item1 | value2 | SOME | and customization.csv that has service specific configuration: | path | item | value | type | |------------|-------|--------|------| | some/path | item2 | value3 | ALL | | new/path | item3 | value3 | SOME | My goal is to merge them and end up with

问题 If I have function names stored as strings in a Hashtable. Is there a way to access the functions via the stored strings? EDIT I'm afraid the platform that i'm working on CLDC1.1/MIDP2.0 does not support Reflection. Any workaround possible? 回答1: Just use a big long list of else-ifs: [...] } else if ("foo".equals(function)) { target. foo(); } else if ("bar".equals(function)) { target. bar(); [...] (Although I generally don't like attempting vertical alignments in source, I think in cases like

问题 I found about Cuckoo Hash tables and they seem pretty good. But most examples code I found implement this using 2 tables. This seems to me wrong because the 2 tables may be in different memory pages and we have overhead of fetching random addresses and have no real locality. Is it not possible to use 1 array instead of 2? Is it perhaps not possible to detect when an element has already been kicked out 2 times and is time for resizing? 回答1: To answer the confusion in the comments: no this is

问题 I have a question regarding hashtable size and modular hashing. The hashing algorithm I'm referring to is the following: hash_key % table_size = array_index. I'm reading an algorithms textbook where the following bit of advice is given: If the table size is not prime, it may be the case that all of the bits of the key do not play a role in determining the array_index. Can anyone explain what this means exactly with an example? 回答1: What you want to avoid is common factors. There is a theorem