正面直接解就行了，先找出重复的项，再通过重复的项找出所有下标进行合并操作最后去重排序
from typing import List
class Solution:
def accountsMerge(self, accounts: List[List[str]]) -> List[List[str]]:
new_array = []
for item in accounts:
new_array.extend(item[1:])
duplicates = {item for item in new_array if new_array.count(item) > 1}
for email in duplicates:
duplicates_index = []
for index, item in enumerate(accounts):
if email in item[1:]:
duplicates_index.append(index)
for item in sorted(duplicates_index[1:], reverse=True):
emails = accounts[duplicates_index[0]][1:] + accounts[item][1:]
accounts[duplicates_index[0]] = [accounts[duplicates_index[0]][0]] + emails
accounts.pop(item)
for item in accounts:
item[1:] = sorted(list(set(item[1:])))
return accounts
accounts = [["David", "David0@m.co", "David4@m.co", "David3@m.co"],
["David", "David5@m.co", "David5@m.co", "David0@m.co"],
["David", "David1@m.co", "David4@m.co", "David0@m.co"],
["David", "David0@m.co", "David1@m.co", "David3@m.co"],
["David", "David4@m.co", "David1@m.co", "David3@m.co"]]
print(Solution().accountsMerge(accounts))