How to create a Hash that includes a dynamically build array of hashes

I need to create something like this:

"paxReference" => [{
  "ptc" => "ADT",                 
  "traveller" => [
    {
      "ref" => "1"               
    },
    { 
      "ref" => "2"
    }
  ]
},
{
  "ptc" => "CH",                 
  "traveller" => [
    {
      "ref" => "3",                 
    },
    {
      "ref" => "4",                
    }
  ]
},
]

But the array of hashes "traveller" must be built dynamically, I mean, If a pararmeter ADT_number is 4, I must include 4

"ref" => "1"
"ref" => "2"
"ref" => "3"
"ref" => "4"

Same thing for the "CH" segment.

How can I do this in Ruby?

The out put should look like this:

<paxReference>
 <ptc>ADT</ptc>
 <traveller>
  <ref>1</ref>
 </traveller>
 <traveller>
  <ref>2</ref>
 </traveller>
</paxReferenc开发者_StackOverflowe>
<paxReference>
 <ptc>CH</ptc>
 <traveller>
  <ref>3</ref>
 </traveller>
 <traveller>
  <ref>4</ref>
 </traveller>
</paxReference>

paxReference = ptcs.map do |ptc|
  out_hash = {}
  out_hash["ptc"] = ptc
  out_hash["traveler"] = ADT_number.times.map {|i| {"ref" => i }}
end

This is in the case that ptcs is an array, and that ADT_number doesn't change for each one. If ADT_number changes, then you'll want to grab something with an index or something like that.