Question

我有一系列哈希，例如

array = [
{ id: 1, name: 'root' parent: null},
{ id: 2, name: 'first' parent: 1},
{ id: 5, name: 'first step' parent: 2},
{ id: 6, name: 'second step' parent: 2},

{ id: 3, name: 'second' parent: 1},
{ id: 7, name: 'first step' parent: 3},

{ id: 4, name: 'third' parent: 1},
{ id: 2, name: 'first' parent: 1},

我需要建立类似的东西

hash = {
  { 
  id: 1,
  name: 'root',
  parent: null,
  childrens: [
    { id: 2,
    name: 'first',
    parent: 1,
    childrens: [
      {
        id: 5,
        name: 'first step',
        parent: 2
      },
      {
        id: 6,
        name: 'second step',
        parent: 2
      },
  ]},
  ...
}

我是ruby的新手，并不了解如何做到这一点。可能我需要使用递归函数？或者不是？

Answer 1

# Put all your nodes into a Hash keyed by id  This assumes your objects are already Hashes
object_hash = nodes.index_by {|node| node[:id]}
object_hash[0] = {:root => true}

# loop through each node, assigning them to their parents
object_hash.each_value {|node|
  next if node[:root]
  children = object_hash[node[:parent_id]][:children] ||= []
  children << node
}

#then your should have the structure you want and you can ignore 'object_hash' variable
tree = object_hash[0]

答案：

Algorithm for parsing a flat tree into a non-flat tree

创建嵌套哈希RUBY

1 个答案: