hash

问题 I have a server to receive request from multiple client. I have done this with threads. I want to insert some user name and password to hash table. For that I am using double hash method. It was inserted successfully. But I want to know when user enter a user name, I need to search on hash table whether this username already present. But I can't do it now. I know the concept like using hashing. Get the index using hashfunction1 through username and use double hash like this. But how can I

问题 Why do the equals methods implemented by Eclipse compare each value, wouldn't it be simpler to just compare the hashCodes of both objects? From what I know: hashCode always generates the same hash for the same input So if two objects are equal, they should have the same hash If objects that are equal have the same hash, I can just check the hash in order to determine of objects are equal or not edit: Related question, why does one always implement the hashCode when equals is implemented, if

问题 I'm doing a project where I'm parsing JSON from the Riot Games API, and I'm having trouble. I'm pretty new to this, so bear with me: The API returns JSON, for example: {"forcinit":{"id":35979437,"name":"F O R C I N it","profileIconId":576,"summonerLevel":30,"revisionDate":1427753158000}} in my code, I have the following: #lang racket (require racket/gui/base net/url json racket/format ) ; --- Query API (define api-request "https://na.api.pvp.net/api/lol/na/v1.4/summoner/by-name/SUMMONER_NAME

问题 I'm trying to fetch some products from this JSON API so I can display them in my views, with bad JSON gracefully handled using Hash#fetch to declare a default value if I get nil. But why am I getting: can't convert String into Integer or if I set @json_text to {} : undefined method 'fetch' for `nil:NilClass` Live app: http://runnable.com/U-QEWAnEtDZTdI_g/gracefully-handle-bad-json class MainController < ApplicationController require 'hashie' def index @json_text = <<END { "products": [] } END

问题 I am trying to use Double Hashing to hash a String key into a hash table. I did something like: protected int getIndex(String key) { int itr = 0, size = this.values.length, index1, index2, index = 0; do { // do double hashing to get index for curr [itr] (iteration) index1 = Math.abs(key.hashCode()) % size; index2 = size - ((key + key + "#!@").hashCode() % size); # trying very hard to eliminate clash, but still fails ... TA and AT gets index 2 when size = 5 index = (index1 + (itr * index2)) %

问题 Why second output shows me only one element of Array ? Is it still Array or Hash already? def printArray(arr) arr.each { | j | k, v = j.first printf("%s %s %s \n", k, v, j) } end print "Array 1\n" printArray( [ {kk: { 'k1' => 'v1' }}, {kk: { 'k2' => 'v2' }}, {kk: { 'k3' => 'v3' }}, ]) print "Array 2\n" printArray( [ kk: { 'k1' => 'v1' }, kk: { 'k2' => 'v2' }, kk: { 'k3' => 'v3' }, ]) exit # Output: # # Array 1 # kk {"k1"=>"v1"} {:kk=>{"k1"=>"v1"}} # kk {"k2"=>"v2"} {:kk=>{"k2"=>"v2"}} # kk {

问题 I have a list named myul (whatever) <ul id="myul"> <li>item 1</li> <li>item 2</li> <li>item 3</li> <li>item 4</li> <li>item 5</li> <li>item 6</li> </ul> and i filter its item using <input id="filter" type="text" value=""/> and script is based on jquery jQuery.expr[':'].containsLower = function(a, i, m) { return jQuery(a).text().toUpperCase() .indexOf(m[3].toUpperCase()) >= 0; // for uppercase-lowercase support }; $('#filter').keyup(function(){ $('ul#myul li').hide().filter(':containsLower("'

问题 I've tried to create a remote MySQL database and link it to WPF application. I manage to do that but I was advised by users from the forum to hash my password, cause it can be easyly SQL injected. My question is does anybody know how can I create hashed password based on that code: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using MySql.Data.MySqlClient;

问题 I have a 2 dimensional array v = [ ["ab","12"], ["ab","31"], ["gh","54"] ] The first element of the subarray of v will have repeating elements, such as "ab" . I want to create a hash that puts the key as the first element of the subarray, and values as an array of corresponding second elements from v . please advice. Further, I want this, h={"ab"=>["12","31"],"gh"=>["54"]} and then I want to return h.values, such that the array [["12","31"],["54"]] is returned 回答1: v.inject(Hash.new{|h,k|h[k]

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",