LeetCode 929 Unique Email Addresses 解題報告
題目要求
Every email consists of a local name and a domain name, separated by the @ sign.
For example, in [email protected], alice is the local name, and leetcode.com is the domain name.
If you add periods (‘.‘) between some characters in the local name part of an email address, mail sent there will be forwarded to the same address without dots in the local name. For example, "[email protected]"
"[email protected]" forward to the same email address. (Note that this rule does not apply for domain names.)
If you add a plus (‘+‘) in the local name, everything after the first plus sign will be ignored. This allows certain emails to be filtered, for example [email protected] will be forwarded to [email protected]
It is possible to use both of these rules at the same time.
Given a list of emails, we send one email to each address in the list. How many different addresses actually receive mails?
Input: ["[email protected]","[email protected]","[email protected]"]
?Output: 2
?Explanation: "[email protected]" and "[email protected]" actually receive mails
1 <= emails[i].length <= 1001 <= emails.length <= 100
?
Each emails[i]contains exactly one ‘@‘ character.
題目分析及思路
題目要求得到一組郵件地址中不重復的地址的個數，規則是用戶名部分有‘.’，則和無‘.’的用戶名一樣；用戶名部分有‘+’，則忽略第一個‘+’後面的部分。兩個規則可以同時生效，但對域名部分不起作用。所以先對郵件進行拆分，分為用戶名部分和域名部分；之後先找到‘+’，去掉‘+’及後面部分，再去掉‘.’。最後再和‘@’及域名連接。因為要去重，所以使用一個set保存所有不重復的結果。
python代碼?
class Solution:
def numUniqueEmails(self, emails):
"""
:type emails: List[str]
:rtype: int
"""
emailsset = set()
for e in emails:
local,domain = e.split("@")
local = local.split("+")[0].replace(".","")
emailsset.add(local+"@"+domain)
return len(emailsset)
LeetCode 929 Unique Email Addresses 解題報告