Carry Combos - Ruby

$results = { 0 => [], 1 => [], 2 => [], 3 => [], 4 => [], 5 => [] }

def get_tens_column (numbers)
    n = 0
    for i in 0...numbers.length
        n += numbers[i]
    end

    return n / 10
end

def dec_to_array (n)
    array = []
    numbers = [1,2,4,8,6,2,4].reverse()
    for i in 0..7
        a = 2.pow(i)
        if (n & a == a)
            array.push(numbers[i])
        end
    end
    return array
end

# Populate the results
for i in 0...128
    combo = dec_to_array(i)
    tens = get_tens_column(combo)
    $results[tens].push({ :array => combo, :decimal => i })
end

# Output Combinations
File.open("./combos.txt", 'w') { |file|
    file.puts "128 total combinations"
    for i in 0...$results.keys.length
        result = $results[$results.keys[i]]
        file.puts "------------|| #{$results.keys[i]} (#{result.length} combos) ||------------"
        for j in 0...result.length
            file.puts "#{result[j][:array].to_s} = #{result[j][:decimal]}"
        end
    end
    file.puts "\n"
    for i in 0...$results.keys.length
        result = $results[$results.keys[i]]
        file.puts "------------|| #{$results.keys[i]} (#{result.length} combos) ||------------"
        for j in 0...result.length
            file.print "#{result[j][:decimal]}"
            if (j < result.length - 1)
                file.print(",")
            end
        end
        file.print("\n")
    end
}


# MAPPING RESULTS
# using: https://www.charlie-coleman.com/experiments/kmap/

# Does 10s column equal 0:
# F = 2'4'6'2'4' + 4'8'2'4' + 2'8'6'2' + 2'4'8'4' + 8'6'4' + 4'8'6'

# Does 10s column equal 1:
# F = 2'862'4' + 2'4'62'4 + 24'86' + 486'2' + 2'486' + 4'864' + 86'24' + 2'86'2 + 2'86'4 + 248'4 + 28'62 + 48'24 + 48'6 + 8'64

# Does 10s column equal 2:
# F = 24824 + 2486 + 2864 + 4862 + 4864 + 8624