Password Validation Rules | Dataford Interview Questions

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Problem

Mistral Solutions firmware uses password validation before accepting credentials through an embedded configuration interface. Implement a validator that returns whether a password satisfies every required rule.

A password is valid if it:

Contains at least one uppercase ASCII letter from A to Z.
Contains at least one digit from 0 to 9.
Contains at least one special character, defined as any character that is not an ASCII letter or digit.
Does not contain consecutive identical characters. The comparison is case-sensitive, so aA is allowed but aa is not.

Formal Specification

Given a string password, return True if all rules are satisfied; otherwise, return False. The input contains printable ASCII characters only. A space counts as a special character.

Constraints

1 <= len(password) <= 10^5
password contains only printable ASCII characters
Uppercase and lowercase characters are distinct
A space is treated as a special character

Function Signature

def validate_password(password):