## Problem A password is secure when all of the following are true: - It has at least six characters. - It contains at least one digit. - It contains at least one lowercase English letter. - It contains at least one uppercase English letter. - It contains at least one character from the exact special-character set `!@#$%^&*()_`. - It contains no space character. Return whether a supplied password is secure. ### Function Contract Implement `isSecurePassword(password)` and return a Boolean. ### Constraints & Assumptions - `0 <= len(password) <= 100`. - Every character is an English letter, digit, ordinary space, or a member of the special set above. - Only the explicitly listed characters count as special. - A password may contain several characters from each category. ### Clarifying Questions to Ask - Do characters such as `-` or `?` count as special? No. - Does a tab count as a space? Tabs are outside the stated input alphabet; reject only the ordinary space character. - Is six characters inclusive? Yes. - Must every requirement be checked even after one fails? No; early return is allowed. ```hint Track independent facts Maintain one Boolean for each required character category and reject immediately if an ordinary space appears. ``` ### Examples - `"FooBar123!"` returns `true`. - `"foobar123!"` returns `false` because it has no uppercase letter. - `"FooBar123"` returns `false` because it has no listed special character. - `"F0bar! F0bar!"` returns `false` because it contains a space. - `"Fo0*"` returns `false` because it is too short. ### Evaluation Focus - Uses the exact special-character set and the inclusive minimum length. - Rejects spaces even when every positive category is present. - Handles empty and boundary-length strings. - Runs in `O(n)` time and `O(1)` auxiliary space. ### Extensions to Discuss 1. How would Unicode letters change category detection? 2. Why is a configurable policy preferable to embedding many enterprise rules in one regular expression? 3. How would you report every failed rule without leaking the password into logs?