问题描述
我在C ++中有以下容器：
I have following container in C++:
std::unordered_map<keyType, std::map<otherKeyType, keyValue>::iterator> Container;
在我的代码中，我使用这个容器来快速访问std :: map容器中的元素，可以同时修改这个地图没有任何问题，总是我的迭代器是有效的（我从这个地图中只删除一个地方的元素）。
Somewhere in my code I use this container to quickly access elements in std::map container, and I can concurrently modify this map without any problems and always my iterators are valid (I remove elements from this map only in one place).
我想重现这种行为在Java ，但我知道Java在标准的TreeMap容器中没有类似的东西。
I want to reproduce this behaviour in Java, but I know that Java doesn't have something like that in standard TreeMap container.
有什么方法保存一个快速路径到TreeMap中的某个元素，这将跳过在这个TreeMap中的对数（时间）搜索？
Is there any way to save a "fast path" to some element in TreeMap, which would skip logarithmic (in time) search in this TreeMap? Should I somehow use references and create my own container, or is there some sort or "magical container" that will fit my needs?
推荐答案
如果您需要有序映射，则可能满足您的需求 - 在splay树中更频繁访问的对象将向顶部倾斜，这会减少其查找时间。有几个Java实现可通过google。另一个选项是维护您从树图访问的最后K个元素的hashmap缓存。
If you need an ordered map, then a splay tree might suit your needs - the more frequently accessed objects in a splay tree will gravitate towards the top, which reduces their lookup time. There are several Java implementations available via google. Another option is to maintain a hashmap cache of the last K elements that you've accessed from the treemap.
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