[saiyam-jain-dev]

Describe your change

Fixes #15633

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

When the number of required characters in chars_incl exceeded the requested length i, �lternative_password_generator performed i -= len(chars_incl), resulting in a negative i. Because Python's modulo on negative numbers yields positive results (-1 % 3 == 2), the generator silently returned a password longer than the requested maximum length instead of enforcing the constraint or raising an error.

This PR:

• Guards �lternative_password_generator with a check ensuring i >= len(chars_incl) and raises a descriptive ValueError otherwise.
• Adds comprehensive doctests to �lternative_password_generator and
  andom.
• Removes legacy commented-out lines.

Checklist

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues, then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".