929 - Unique Email Addresses\.
Easy
Every **valid email** consists of a **local name** and a **domain name** , separated by the `'@'` sign. Besides lowercase letters, the email may contain one or more `'.'` or `'+'`.
* 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. Note that this rule **does not apply** to **domain names**.
* For example, `"
[email protected]"` and `"
[email protected]"` forward to the same email address.
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. Note that this rule **does not apply** to **domain names**.
* For example, `"
[email protected]"` will be forwarded to `"
[email protected]"`.
It is possible to use both of these rules at the same time.
Given an array of strings `emails` where we send one email to each `emails[i]`, return _the number of different addresses that actually receive mails_.
**Example 1:**
**Input:** emails = ["
[email protected]","
[email protected]","
[email protected]"]
**Output:** 2
**Explanation:** "
[email protected]" and "
[email protected]" actually receive mails.
**Example 2:**
**Input:** emails = ["
[email protected]","
[email protected]","
[email protected]"]
**Output:** 3
**Constraints:**
* `1 <= emails.length <= 100`
* `1 <= emails[i].length <= 100`
* `emails[i]` consist of lowercase English letters, `'+'`, `'.'` and `'@'`.
* Each `emails[i]` contains exactly one `'@'` character.
* All local and domain names are non-empty.
* Local names do not start with a `'+'` character.
* Domain names end with the `".com"` suffix.