Format a Forest of Nested Comments

Question

The question asks the candidate to implement a function that formats a forest of nested comments, ensuring proper indentation and structure.

Codemia · Accepted Answer

To format a forest of nested comments, we need to traverse the data structure recursively. Each comment can have child comments, and we need to ensure that the indentation reflects the depth of each comment in the hierarchy. We will use a depth-first search approach to navigate through the comments.

We can define a recursive function that takes a list of comments and the current indentation level as parameters. For each comment, we will print it with the appropriate indentation and then call the function recursively for its child comments. Here is a sample implementation in Python:

```python
class Comment:
    def __init__(self, text, children=None):
        self.text = text
        self.children = children if children is not None else []

def format_comments(comments, level=0):
    for comment in comments:
        print(' ' * (level * 4) + comment.text)  # 4 spaces per level
        format_comments(comment.children, level + 1)
```
This implementation uses a simple recursive function to handle the formatting.

The time complexity of this algorithm is O(n), where n is the total number of comments, since we visit each comment exactly once. The space complexity is O(h), where h is the height of the comment tree, due to the recursion stack.

We should consider edge cases such as an empty list of comments or comments without children. In both cases, the function should handle these gracefully without errors. Additionally, we should ensure that the formatting remains consistent regardless of the input structure.

Interviewers are looking for clarity in the candidate's thought process, the ability to write clean and efficient code, and a solid understanding of recursion and data structures. They also appreciate candidates who can articulate their reasoning and consider edge cases during their explanation.

Format a Forest of Nested Comments

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