#1

Every email consists of a local name and a domain name, separated by the @ sign.

For example, in `alice@leetcode.com``alice` is the local name, and `leetcode.com` is the domain name.

Besides lowercase letters, these emails may contain `'.'`s or `'+'`s.

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, `"alice.z@leetcode.com"` and `"alicez@leetcode.com"` 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 `m.y+name@email.com` will be forwarded to `my@email.com`.  (Again, this rule does not apply for domain names.)

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?

Example 1:

```Input: ["test.email+alex@leetcode.com","test.e.mail+bob.cathy@leetcode.com","testemail+david@lee.tcode.com"]
Output: 2
Explanation: "testemail@leetcode.com" and "testemail@lee.tcode.com" actually receive mails
```

Note:

• `1 <= emails[i].length <= 100`
• `1 <= emails.length <= 100`
• Each `emails[i]` contains exactly one `'@'` character.

#2

This question is basically asking for number of unique emails in the given list. The below code processes each email and stores them in a map and finally return the size of the map, that is basically the number of unique emails in the list.

``````func numUniqueEmails(emails []string) int {
if len(emails)==0{
return 0
}

emailMap := make(map[string]bool, 0)
for _, email := range emails{
if !emailMap[cleanEmail(email)]{
emailMap[cleanEmail(email)] = true
}
}

return len(emailMap)
}

func cleanEmail(email string) string {
nameDomain := strings.Split(email, "@")

namePlus := strings.Split(nameDomain[0], "+")
nameWithDots := strings.Split(namePlus[0], ".")
finalName := strings.Join(nameWithDots, "")

return finalName+nameDomain[1]
}
``````