Leetcode 1148 - Article Views I

Problem

Examples

Solution

Method 1 - Using Distinct and Equality

Code

SQL

select distinct author_id as id from Views
where author_id = viewer_id 
order by id;

Pandas

• Create a new DataFrame named authors_viewed_own_articles by filtering the rows where the author_id and viewer_id are the same. This will give us the rows where authors viewed their own articles.

• Extract the unique author_id values from the DataFrame authors_viewed_own_articles. We want to find the unique authors who viewed at least one of their own articles.

• Sort the unique author_id values in ascending order to get the list of authors who viewed at least one of their own articles.

• Create a new DataFrame named result_df with a single column named id containing the sorted unique author_id values.

• Return the result_df, which will contain the list of authors who viewed at least one of their own articles, sorted by their IDs in ascending order.

import pandas as pd

def article_views(views: pd.DataFrame) -> pd.DataFrame:
    authors_viewed_own_articles = views[views['author_id'] == views['viewer_id']]
    
    unique_authors = authors_viewed_own_articles['author_id'].unique()
    
    unique_authors = sorted(unique_authors)
    
    result_df = pd.DataFrame({'id': unique_authors})
    
    return result_df

Complexity

• Time: O(n)
• Space: O(1)