java - 字典条目数组的数据结构

Question

我正在 java 中寻找一种本地方式(最好)来实现一种数据结构，以将 int 作为键和一组键/值对作为值。本质上 if 是一个由索引引用的字典数组。

例如:

MyDataStructure[[Key,Value]] foo = new ...

foo.put[["hello", "world"], ["so","rocks"]]

println(foo[0].getValue("hello")) 会打印出 "world" 和 println(foo[0].getValue( "so")) 会打印出 "rocks"

Answer 1

• 如果你事先知道字典的数量，那么最小结构是 Map 数组:

  Map<Key,Value>[] dictonaires = new HashMap<Key,Value>[20];
  for (int i=0; i<dictionaries.length; i++) {
      dictionaries[i] = new Hashmap<Key,Value>();
  }
  
  // Any time later, refer to a dictionary by index 
  Map<Key,Value> currentDictionary = dictionaries[10];
  // Can call currentDictionar.put/get/remove to create or update/read/delete 
  // entries, but can't add/remove entire dictionaries
  

• 但更灵活的结构是List<Map<Key,Value>> ，因为词典的数量可以动态变化。任何List会工作 - 但在你的情况下，ArrayList最适合通过索引快速访问(获取):

  List<Map<Key,Value>> dictionaryList = new ArrayList<Map<Key,Value>>();
  
  // Then add new dictionary anytime later:
  dictionaryList.add(new HashMap<Key,Value>());    
  
  // Access by index (index matches order of adding):
  Map<Key,Value> currentDictionary = dictionaryList.get(10);    
  // Can call currentDictionar.put/get/remove to create or update/read/delete 
  // entries, but can't add/remove entire dictionaries
  
  // Or even remove entire dictionary by index:
  dictionaryList.remove(10);