hashmap

问题 This is a followup question to What is the initial size of Array in HashMap Architecture?. From that question I understand the initial capacity of HashMap is 16 by default which allows up to 11 entries before resizing since the default load factor is 0.75. When does the rehashing take place? After 11 entries in the array or 11 entries in one of the linked lists? I think after 11 entries in the array. Since the array size is 16 a HashMap could contain many objects (maybe more than 16) in a

问题 Since I need to get the key values of double value I' m using BiMap . BiMap<String,Double>mapObj = HashBiMap.create(); mapObj.put("a1",3.58654); mapObj.put("a2",4.1567); mapObj.put("a3",4.2546); For a particular value like 4.0156 I must get the key value a2.. that is if, Double value=4.0156; mapObj.inverse().get(value)=a2 I tried many ways but its getting always null, since there is no exact match. please anyone help me... if I have chosen a wrong way please correct it because I'm new in Java

问题 I need to sort a hash map, first according to value then according to key. TreeMap<String,Integer> dictionary = new TreeMap<String,Integer>(); For example, the desired output is something like: it - 2 of - 2 the - 2 times - 2 was - 2 best - 1 worst - 1 I tried tree map, but that only sorts it according to key. So basically, I need to sort my first according to the Integer (Highest to Lowest) and then according to the String (First A then B till Z). I searched online and saw that I'm gonna

问题 I'm writing a Java program which adds all of the words on a website into a HashMap, and then assigns them a key of how many times they appear on the page. For instance, if I ran it on a page with only the words "hello, java, coffee, java", the output would be Java : 2 Coffee : 1 Hello : 1 This also ignores certain words that I don't want included. Here's what I have so far. Map<String, Integer> found = new HashMap<>(); // (word,frequency) Matcher match = Pattern.compile(word_pattern).matcher

问题 I have a hashMap that needs to travel from server to client over network. Now when the size increases beyond some limit provided at socket buffer the following exception is thrown. Caused by: weblogic.socket.MaxMessageSizeExceededException: Incoming message of size: '3002880' bytes exceeds the configured maximum of: '3000000' bytes for protocol: 't3' While googling it out I found that the socket size should be increased but that is not required as this is not such a good solution. Then I am

问题 I'm having some trouble creating a copy constructor for my hash map class right now. Currently, I understand how to do a copy constructor for arrays, by copying things over from the original array to the next. For example, here is what would be done for an array list: ArrayList::ArrayList(const ArrayList& a) : items{new std::string[a.cap]}, sz{a.sz}, cap{a.cap} { // arrayCopy is a for loop that does items[i] = a.items[i] on each iteration arrayCopy(items, a.items, sz); } I understand that we

问题 I am constructing a list of hash maps which is then passed to another function. When I try to print each hash maps from the list using map it is not working. I am able to print the full list or get the first element etc. (defn m [a] (println a) (map #(println %) a)) The following works from the repl only. (m (map #(hash-map :a %) [1 2 3])) But from the program that I load using load-file it is not working. I am seeing the a but not its individual elements. What's wrong? 回答1: In Clojure

问题 Assuming that I have a hashtable: $tokens = @{ Id=9999; Title="Lorem ipsum dolor sit amet"; Author=@{Name="John Doe"; Email='john.doe@foo.xyz'}; Analyst=@{Name="Jane Doe"; Email='jane.doe@foo.xyz'} } And a template that I would like to populate, replacing the tokens (e.g. __Title__ ) with the corresponding hashtable's value: /* Author: __Author.Name__ <__Author.Email__> Analyst: __Analyst.Name__ <__Analyst.Email__> Request: __Title__ [__Id__] */ ... Should become: /* Author: John Doe <john

问题 In java HashSet is implemented using a HashMap. So when we add an item to the set the following code is executed. public boolean add(E e) { return map.put(e, PRESENT)==null; } what happens when two objects that are different but having equal hash is added to the HashSet; will it (HashSet) contain both the objects or what happens then? 回答1: hashmap uses .equals() as well as .hash() . two things are not the same unless .equals() returns true. the same will be true of hashset. so if two objects

问题 I have a hashmap which is public HashMap<String, ArrayList<Integer>> invertedList; I show you my invertedList in watch list during debugging: invertedList.toString(): "{ryerson=[0, 2, 3], 23=[3], award=[1], andisheh=[0, 2]}" In the same watch list when I enter: invertedList.get("ryerson") I get null as result, also in the code. As you can see "ryerson" is already there as a key in my invertedList and I should get [0, 2, 3] as a result!!! What is happening here? I'm so confused! I know there