Append increment number to duplicate item in array of objects [closed] - ruby

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There are duplicate items in the array. I want to append an incremental number to such items. For example:
Input:
[
{id: 1, name: "john"},
{id: 2, name: "Man"},
{id: 3, name: "Man"},
{id: 4, name: "john"},
{id: 5, name: "kind"},
{id: 6, name: "nova"},
{id: 7, name: "kind"},
{id: 8, name: "fred"},
{id: 9, name: "fred"},
{id: 10, name: "john"}
]
Expected output:
[
{id: 1, name: "john-1"},
{id: 2, name: "Man-1"},
{id: 3, name: "Man-2"},
{id: 4, name: "john-2"},
{id: 5, name: "kind-1"},
{id: 6, name: "nova"},
{id: 7, name: "kind-2"},
{id: 8, name: "fred"},
{id: 9, name: "monk"},
{id: 10, name: "john-3"}
]

Answer 1

the input data can be huge, is there any way to mutate the same object and find only duplicate to reduce the latency and memory
Something like this would work:
input
.group_by { |item| item[:name] }
.reject { |_name, entries| entries.count == 1 }
.each do |_name, entries|
entries.each.with_index(1) do |entry, index|
entry[:name] << "-#{index}"
end
end
It groups the items by their :name key and rejects those with only 1 entry. It then traverses the remaining groups (i.e. with 2 or more entries) and appends the 1-bases index to each entry's name.
Afterwards, input will be:
[{:id=>1, :name=>"john-1"},
{:id=>2, :name=>"Man-1"},
{:id=>3, :name=>"Man-2"},
{:id=>4, :name=>"john-2"},
{:id=>5, :name=>"kind-1"},
{:id=>6, :name=>"nova"},
{:id=>7, :name=>"kind-2"},
{:id=>8, :name=>"fred-1"},
{:id=>9, :name=>"fred-2"},
{:id=>10, :name=>"john-3"}]

Answer 2

This is some quick example with given input:
input
.group_by { |value| value[:name] }
.values
.select { |x| x.map.with_index(1) { |y, i| p y[:name] = "#{y[:name]}-#{i}" } }
.flatten
And thats the output:
[{:id=>1, :name=>"john-1"},
{:id=>4, :name=>"john-2"},
{:id=>10, :name=>"john-3"},
{:id=>2, :name=>"Man-1"},
{:id=>3, :name=>"Man-2"},
{:id=>5, :name=>"kind-1"},
{:id=>7, :name=>"kind-2"},
{:id=>6, :name=>"nova-1"},
{:id=>8, :name=>"fred-1"},
{:id=>9, :name=>"fred-2"}]
Group by will group input by duplicated names. I don't know if you tried anything but this is something that you can start work with and improve.

Answer 3

Tried to mutate the same input and incremented the values in name string
orders = [{:id=>2, :name=>"Man"}, {:id=>3, :name=>"Man"}, {:id=>8, :name=>"fred"}, {:id=>9, :name=>"fred"},{:id=>5, :name=>"kindaa"}, {:id=>1, :name=>"john"}, {:id=>4, :name=>"john"}, {:id=>10, :name=>"john"}, {:id=>5, :name=>"kinda"}, {:id=>5, :name=>"kind"}, {:id=>7, :name=>"kind"}, {:id=>6, :name=>"nova"}, {:id=>11, :name=>"nova"}]
counter = 1
orders.each_with_index do |order, index|
if index < orders.length - 1
if order[:name] == orders[index + 1][:name]
orders[index][:name] = orders[index][:name].to_s + "-#{counter}"
counter = counter + 1
else
orders[index][:name] = orders[index][:name].to_s + "-#{counter}" if counter > 1
counter = 1
end
else
orders[index][:name] = orders[index][:name].to_s + "-#{counter}" if counter > 1
end
end
puts orders
Output:
{:id=>2, :name=>"Man-1"}
{:id=>3, :name=>"Man-2"}
{:id=>8, :name=>"fred-1"}
{:id=>9, :name=>"fred-2"}
{:id=>5, :name=>"kindaa"}
{:id=>1, :name=>"john-1"}
{:id=>4, :name=>"john-2"}
{:id=>10, :name=>"john-3"}
{:id=>5, :name=>"kinda"}
{:id=>5, :name=>"kind-1"}
{:id=>7, :name=>"kind-2"}
{:id=>6, :name=>"nova-1"}
{:id=>11, :name=>"nova-2"}