new_contents: """Leetcode 721. Accounts Merge
  Medium
  
  URL: https://leetcode.com/problems/accounts-merge/
  
  Given a list accounts, each element accounts[i] is a list of strings, where the
  first element accounts[i][0] is a name, and the rest of the elements are emails
  representing emails of the account.
  
  Now, we would like to merge these accounts. Two accounts definitely belong to the
  same person if there is some email that is common to both accounts. Note that even
  if two accounts have the same name, they may belong to different people as people
  could have the same name. A person can have any number of accounts initially,
  but all of their accounts definitely have the same name.
  
  After merging the accounts, return the accounts in the following format: the first
  element of each account is the name, and the rest of the elements are emails in
  sorted order. The accounts themselves can be returned in any order.
  
  Example 1:
  Input: 
  accounts = [["John", "johnsmith@mail.com", "john00@mail.com"], 
  ["John", "johnnybravo@mail.com"], ["John", "johnsmith@mail.com", 
  "john_newyork@mail.com"], ["Mary", "mary@mail.com"]]
  Output: [["John", 'john00@mail.com', 'john_newyork@mail.com', 
  'johnsmith@mail.com'],  ["John", "johnnybravo@mail.com"], ["Mary", "mary@mail.com"]]
  Explanation: 
  The first and third John's are the same person as they have the common email
  "johnsmith@mail.com".
  The second John and Mary are different people as none of their email addresses are
  used by other accounts.
  We could return these lists in any order, for example the answer [['Mary',
  'mary@mail.com'], ['John', 'johnnybravo@mail.com'], 
  ['John', 'john00@mail.com', 'john_newyork@mail.com', 'johnsmith@mail.com']]
  would still be accepted.
  
  Note:
  - The length of accounts will be in the range [1, 1000].
  - The length of accounts[i] will be in the range [1, 10].
  - The length of accounts[i][j] will be in the range [1, 30].
  """
  
  class Solution(object):
      def accountsMerge(self, accounts):
          """
          :type accounts: List[List[str]]
          :rtype: List[List[str]]
          """
          pass
  
  
  def main():
      pass
  
  
  if __name__ == '__main__':
      main()
  
subject: Add lc0721_accounts_merge.py