hashtable

问题 I saw in some of the forums that people used: 7-(key mod 7) or 6-(key mod 6) This is used for computing the second hash function of Double Hashing for any large values of the key. Is there any importance to the usage of that 6(not even a prime no.) or 7? Or is it just to randomly generate some value unlike linear probing and quadratic probing? References: http://www.java2s.com/Code/Java/Collections-Data-Structure/Hashtablewithdoublehashing.htm http://www.cse.unt.edu/~donr/courses/2050

问题 I really want to create a HashTable in SML, it seems there already is a structure for this in SML/NJ. The question is, how do I use it? I've not fully understood how to use structures in SML, and some of the very basic examples in the book I read gives me errors I don't even know how to correct, so using the HashTable structure might be an easy thing, but I wouldn't know. If someone could explain this, then that'd be wonderful too! I'm thinking it's something like this: val ht : string * int

问题 I have an object that I need to pass between 2 Activity . The object has HashTable, String[], etc. Can't make out how to make it Parcalebale so that I can populate an array of the object and pass single obj or array to other Activity. My class is : public class TrainRoute { // implements Parcelable private String RouteName; private int RouteIndex; private Context ctx; private Hashtable<String, String> stationsList; private String[] stationsNames; private String[] trainTimings; private boolean

问题 I am going to use GLib's Hash table implementation in a C program and just for now I am just experimenting with it. I wrote the following piece of code for testing: #include <glib.h> #include <stdlib.h> #include <stdint.h> #include <stdio.h> #include <string.h> int main(){ // Some codes and declerations here GHashTable *g_hash_table; uint32_t *a; a=(uint32_t *)malloc(sizeof(uint32_t)); if(a==NULL){ printf("Not Enough Mem For a\n"); return 1; } *a=1123231; uint32_t* key; key=(uint32_t *)malloc

问题 I've been using the TBucketList and TObjectBucketList for all my hashing needs, but never experiemented with switching the number of buckets. I vaguely remember what this means from Data Structures class, but could someone elaborated on the nuances of this particular class in Delphi The following table lists the possible values: Value Number of buckets bl2 2 bl4 4 bl8 8 bl16 16 bl32 32 bl64 64 bl128 128 bl256 256 回答1: TBucketList and TObjectBucketList store pointers. The hash function they

问题 I need to implement an n:m relation in Java. The use case is a catalog. a product can be in multiple categories a category can hold multiple products My current solution is to have a mapping class that has two hashmaps. The key of the first hashmap is the product id and the value is a list of category ids The key to the second hashmap is the category id and the value is a list of product ids This is totally redundant an I need a setting class that always takes care that the data is stored

问题 I need to implement an n:m relation in Java. The use case is a catalog. a product can be in multiple categories a category can hold multiple products My current solution is to have a mapping class that has two hashmaps. The key of the first hashmap is the product id and the value is a list of category ids The key to the second hashmap is the category id and the value is a list of product ids This is totally redundant an I need a setting class that always takes care that the data is stored

问题 I am at my wits end. I am new to powershell and I have tried everything I have been able to find on this subject online. What I am trying to do is print a hashtable of arrays to a file without the stupid ellipsis appearing at the end of each array value. Below is my best attempt. # Update output buffer size to prevent clipping in output window. if( $Host -and $Host.UI -and $Host.UI.RawUI ) { $rawUI = $Host.UI.RawUI $oldSize = $rawUI.BufferSize $typeName = $oldSize.GetType( ).FullName $newSize

问题 I have the following hash of countries; COUNTRIES = { 'Albania' => 'AL', 'Austria' => 'AT', 'Belgium' => 'BE', 'Bulgaria' => 'BG', ..... } Now when I output the hash the values are not ordered alphabetically AL, AT, BE, BG ....but rather in a nonsense order (at least for me) How can I output the hash having the values ordered alphabetically? 回答1: Hashes have no internal ordering. You can't sort a Hash in place, but you can use the Hash#sort method to generate a sorted array of keys and values

问题 What is the easiest way to traverse a hashtable's keys in ascending alphabetical order? 回答1: This is fairly dependent upon what the type of the key is. But lets assume for a minute that they are strings. You could use the following LINQ query Hashtable table = GetHashTable(); var keys = table.Keys.Cast<String>().OrderBy(x => x); For more complex structures the LINQ query is only slightly different. Lets assume you had the following definition for a key struct Name { public string First;