反向地图查找 [英] Reverse map lookup

问题描述

我有一个1对1的地图。从值中查找键的最好方法是什么？

即

p>

键值

  a 1 
b 2 
c 3 
d 4 
  

我想能找到对应于3的那个键。

谢谢！

解决方案

关于它。您可以选择使用两个地图，使用多键地图，例如 Boost多索引库，或执行线性搜索。

更新：最轻巧的开箱即用解决方案似乎< a href =http://www.boost.org/doc/libs/release/libs/bimap/doc/html/index.html> Boost.Bimap ，它代表双向地图。 / p>

I have a 1 to 1 map. What's the best way to find keys from values,

i.e.

For examples if the map is this

KEY VALUE

a    1
b    2
c    3 
d    4

I want to be able to find that key corresponding to 3 is C.

Thanks!

解决方案

There isn't much you can do about it. Your have options to work with two maps, use multi-key map like one from Boost Multi-Index library, or do linear search.

UPDATE: The most lightweight out of the box solution seems to be Boost.Bimap, which stands for bi-directional map.

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