831 - Masking Personal Information.

Medium

You are given a personal information string s, representing either an email address or a phone number. Return the masked personal information using the below rules.

Email address:

An email address is:

• A name consisting of uppercase and lowercase English letters, followed by

• The '@' symbol, followed by

• The domain consisting of uppercase and lowercase English letters with a dot '.' somewhere in the middle (not the first or last character).

To mask an email:

• The uppercase letters in the name and domain must be converted to lowercase letters.

• The middle letters of the name (i.e., all but the first and last letters) must be replaced by 5 asterisks "*****".

Phone number:

A phone number is formatted as follows:

• The phone number contains 10-13 digits.

• The last 10 digits make up the local number.

• The remaining 0-3 digits, in the beginning, make up the country code.

• Separation characters from the set {'+', '-', '(', ')', ' '} separate the above digits in some way.

To mask a phone number:

• Remove all separation characters.

• The masked phone number should have the form:

• "XXXX" is the last 4 digits of the local number.

Example 1:

Input: s = "[email protected]"

Output: "l\*\*\*\*\*[email protected]"

Explanation: s is an email address.

The name and domain are converted to lowercase, and the middle of the name is replaced by 5 asterisks.

Example 2:

Input: s = "[email protected]"

Output: "a\*\*\*\*\*[email protected]"

Explanation: s is an email address.

The name and domain are converted to lowercase, and the middle of the name is replaced by 5 asterisks.

Note that even though "ab" is 2 characters, it still must have 5 asterisks in the middle.

Example 3:

Input: s = "1(234)567-890"

Output: "\*\*\*-\*\*\*-7890"

Explanation: s is a phone number.

There are 10 digits, so the local number is 10 digits and the country code is 0 digits.

Thus, the resulting masked number is "\*\*\*-\*\*\*-7890".

Constraints:

• s is either a valid email or a phone number.

• If s is an email:

• If s is a phone number: