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hashmap - 是否有允许搜索一系列键的 julia 结构？

问题描述

我知道我可以将整数键用于哈希映射，如下面的字典示例。但是字典是无序的，并且不能从整数键中受益。

julia> hashmap = Dict( 5 => "five", 9 => "nine", 16 => "sixteen", 70 => "seventy")
Dict{Int64,String} with 4 entries:
  9  => "nine"
  16 => "sixteen"
  70 => "seventy"
  5  => "five"

julia> hashmap[9]
"nine"

julia> hashmap[8:50] # I would like to be able to do this to get keys between 8 and 50 (9 and 16 here)
ERROR: KeyError: key 8:50 not found
Stacktrace:
 [1] getindex(::Dict{Int64,String}, ::UnitRange{Int64}) at ./dict.jl:477
 [2] top-level scope at REPL[3]:1

我正在寻找一种有序结构，允许访问一定范围内的所有键，同时由于排序键而受益于性能优化。

标签： hashmaprangejulia

解决方案

有一个名为的专用库DataStructures，它具有SortedDict结构和相应的搜索功能：

using DataStructures
d = SortedDict(5 => "five", 9 => "nine", 16 => "sixteen", 70 => "seventy")

st1 = searchsortedfirst(d, 8)   # index of the first key greater than or equal to 8
st2 = searchsortedlast(d, 50)  # index of the last key less than or equal to 50

现在：

julia> [(k for (k,v) in inclusive(d,st1,st2))...]
3-element Array{Int64,1}:
  9
 16

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