# [RUBY] Array pattern calculation and extraction program

It is an output because I programmed it in practice. This time, the code was refreshing personally.

#### `qiita.rb`

``````
number = gets.chomp.split(' ').map{|i| i .to_i}
total = []

number.permutation(4) do |n|
total.push((n[0]*10+n[1]) + (n[2]*10 + n[3]))
end

puts total.max
``````

-Cut the four numbers you entered into two and give each one a tens place or a ones place. ・ Add the resulting two-digit numbers. ・ Apply it to all four numbers entered in advance -The one with the largest total value was output.

I think it's easy to understand, so the processing content is as follows.

#### `qiita.rb`

``````
# Entered value
1 2 3 4

#Pattern output
46　←12+ 34
55　←34+ 21
37 or less all patterns
55
37
46
55
64
37
64
37
55
55
73
46
73
46
55
64
73
55
73
55
64

#Maximum value 73
``````
• Actually, the pattern output is also omitted.

In doing this, I somehow came up with the flow of processing. If I was just trying to find out how to extract the pattern of the array sequence I found a permutation.

Reference article https://qiita.com/shshimamo/items/5a458ecc88e7c24d5112