class Solution:    def numUniqueEmails(self, emails: 'List[str]') -> 'int':        accept = []        for email in emails:            local = email.split('@')[0]            domain = email.split('@')[1]            if '+' in local:                local = local.split('+')[0]            if '.' in local:                local = local.replace('.','')            result = local+domain            if result not in accept:                accept.append(result)        return len(accept)

　其中：速度76ms，内存12.7M

　优化一：使用set直接去重复，使用''.join()进行字符拼接

class Solution:    def numUniqueEmails(self, emails: 'List[str]') -> 'int':        accept = set()        for email in emails:            local,domain = email.split('@')            local = ''.join(local.split('+')[0].split('.'))            result = local + '@' +domain            accept.add(result)        return len(accept)

　　速度：48ms，内存12.6M

优化二：使用map映射的方式，不用手动申请内存，可能map函数自动申请了内存，所以内存没有降下来。

class Solution:    def numUniqueEmails(self, emails: 'List[str]') -> 'int':        def processone(email):            i = email.find('@')            j = email.find('+')            if j < i and j>0:                return ''.join(email[:j].split('.')) + email[i:]            elif j == 0:                return email[i:]            else:                return ''.join(email[:i].split('.')) + email[i:]                return len(set(map(processone,emails)))

　　速度：44ms,内存12.5M