# ---
# title: 482. License Key Formatting
# id: problem482
# author: Indigo
# date: 2021-02-03
# difficulty: Easy
# categories: 
# link: <https://leetcode.com/problems/license-key-formatting/description/>
# hidden: true
# ---
# 
# You are given a license key represented as a string S which consists only
# alphanumeric character and dashes. The string is separated into N+1 groups by
# N dashes.
# 
# Given a number K, we would want to reformat the strings such that each group
# contains _exactly_ K characters, except for the first group which could be
# shorter than K, but still must contain at least one character. Furthermore,
# there must be a dash inserted between two groups and all lowercase letters
# should be converted to uppercase.
# 
# Given a non-empty string S and a number K, format the string according to the
# rules described above.
# 
# **Example 1:**  
# 
#     
#     
#     Input: S = "5F3Z-2e-9-w", K = 4
#     
#     Output: "5F3Z-2E9W"
#     
#     Explanation: The string S has been split into two parts, each part has 4 characters.
#     Note that the two extra dashes are not needed and can be removed.
#     
# 
# **Example 2:**  
# 
#     
#     
#     Input: S = "2-5g-3-J", K = 2
#     
#     Output: "2-5G-3J"
#     
#     Explanation: The string S has been split into three parts, each part has 2 characters except the first part as it could be shorter as mentioned above.
#     
# 
# **Note:**  
# 
#   1. The length of string S will not exceed 12,000, and K is a positive integer.
#   2. String S consists only of alphanumerical characters (a-z and/or A-Z and/or 0-9) and dashes(-).
#   3. String S is non-empty.
# 
# 
## @lc code=start
using LeetCode

function license_key_formatting(S::String, K::Int)
    res = ""
    cnt = 0
    for i in length(S):-1:1
        if cnt == K
            res *= '-'
            cnt = 0
        end
        if S[i] != '-'
            res *= uppercase(S[i])
            cnt += 1
        end
    end
    reverse(res)
end
## @lc code=end
