Leetcode 38: count and say

leetcode_38_count_and_say.rb

Leetcode 38: count and say

# @param {Integer} n
# @return {String}
def count_and_say(n)
    return "1" if n == 1
    str = count_and_say(n-1)
    str = str.split("").map {|ch| ch.to_i}
    #str.tally.map{|k,v| "#{v}#{k}" }.join("")
    len = str.length
    return "1#{str[0]}" if len == 1
    curr_count = 1
    str_to_r = ""
    (1..len-1).each do |i|
        if str[i] == str[i-1]
            curr_count += 1
        else
            str_to_r << "#{curr_count}#{str[i-1]}"
            curr_count = 1
        end
    end
    str_to_r << "#{curr_count}#{str[-1]}"
end