How to get an array of dates with specific values ​​in Rails?

Question

Ruby on Rails

I've been trying to figure this out for a few days now, but I can't figure it out.
Essence of the question:
There is an array of the form [{"yyyy-mm-dd": 2}, {"yyyy-mm-dd": 6}], that is, the content is a set of hashes with dates as keys and numbers as values.
What I'm trying to get: an array that lists all dates for the past year (1.year.ago..Date.today) as keys with values ​​from the first array.
That is, let's say, the first array I have contains the following data:
"2014-05-31": 3 , "2014-06-01": 5
And the second array has 365 hashes, the keys in which are the dates of each day of the year . The values ​​are substituted from the first array and as a result I should get an array like
"2014-05-29": 0, ""2014-05-31": 3 , "2014-06-01": 5 , "2014-06-02": 0
Bold indicates the data of the first array, substituted into the second one.
Please tell me how can I do something like this? I've tried running through an if-elsif-else nested within another if-elsif-else, but I end up with an array of dates that only contains the last value.
I hope I explained it clearly enough, if not, I will try to clarify, just ask.

Answer 1

Not very pretty, but what do you need?

a = [{"2014-05-31" => 3}, {"2014-06-01" => 5}]
b = [{"2014-05-29" => 0}, {"2014-05-30" => 0}, {"2014-05-31" => 0}, {"2014-06-01" => 0}, {"2014-06-02" => 0}]
a.each {|c| b.select {|s| s.keys.first == c.keys.first}.first[c.keys.first] = c.values.first}

Answer 2

You can do this:
if the data in array A is unique:

a = [{"yyyy-mm-dd" => 2}, {"yyyy-mm-dd" => 6}]
b = [{"2014-01-01" => 0} ... {"2014-12-31" => 0}]

ah = Hash[*a.map(&:to_a).flatten]
bh = Hash[*b.map(&:to_a).flatten]
result = bh.merge(ah).map{|k,v| {k => v}}

if not unique:

ah = {}.tap{ |out| a.each{ |h| h.each{ |k,v| (out[k]||=[]) << v } } }
bh = Hash[*b.map(&:to_a).flatten]
result = bh.merge(ah).map{|k,v| {k => v}}