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Recursion Practice

In Doc2Doc, we might have documents nested inside other documents, forming a kind of tree. You know how crazy .docx files can get...

Anyway, we want to find out how deeply nested a given document is.

Assignment

Complete the count_nested_levels function. It takes a dictionary of nested documents, the target document ID, and the current level of the document.

Iterate over the nested_documents dictionary. For each:
1. If the current document_id matches the target_document_id, return its level of nesting.
2. Otherwise, recursively call count_nested_levels on the nested dictionary for this document_id, with the level incremented by 1.
3. If the recursive call found the target_document_id's level, return it.
If the target_document_id doesn't exist, the function should return -1.

Example

In this dictionary, the document with ID 3 is nested 2 levels deep. Document 2 is nested 1 level deep.

nested_documents: dict[int, dict] = {1: {3: {}}, 2: {}}

Tips

The -1 return value is the "not found" signal. If a recursive call returns -1, the target isn't in that branch.