420 - Strong Password Checker.

Hard

A password is considered strong if the below conditions are all met:

• It has at least 6 characters and at most 20 characters.

• It contains at least one lowercase letter, at least one uppercase letter, and at least one digit.

• It does not contain three repeating characters in a row (i.e., <code>"B<ins> aaa </ins>bb0"</code> is weak, but <code>"B**<ins>aa</ins>**b<ins> a </ins>0"</code> is strong).

Given a string password, return the minimum number of steps required to make password strong. if password is already strong, return 0.

In one step, you can:

• Insert one character to password,

• Delete one character from password, or

• Replace one character of password with another character.

Example 1:

Input: password = "a"

Output: 5

Example 2:

Input: password = "aA1"

Output: 3

Example 3:

Input: password = "1337C0d3"

Output: 0

Constraints:

• 1 <= password.length <= 50

• password consists of letters, digits, dot '.' or exclamation mark '!'.