Is Premier League Table Ranking easy or hard?

Premier League Table Ranking is considered an easy database problem. The challenge mainly tests familiarity with SQL window functions and ordering rules rather than complex algorithms or data structures.

Premier League Table Ranking Python/Java solution

In SQL environments like MySQL, use RANK() OVER (ORDER BY ...) to assign positions. In Python with Pandas, sort the DataFrame using sort_values() and compute rankings using the rank() method or by resetting the index after sorting.

How to solve Premier League Table Ranking in O(n)?

A strict O(n) solution is generally not possible because the table must be ordered by ranking rules such as points and goal difference. Sorting requires O(n log n) time in relational databases. Once sorted, computing the rank itself is linear.

What is the best approach for Premier League Table Ranking?

The best approach uses a SQL window function such as RANK() or DENSE_RANK() with an ORDER BY clause on the ranking criteria (points, goal difference, etc.). The database sorts the rows and assigns positions automatically. This method is concise, efficient, and commonly expected in database interviews.

Is Premier League Table Ranking asked at Google/Amazon/Meta?

Database ranking queries appear frequently in interviews at large tech companies and data-focused roles. Variations involving window functions, leaderboards, and ranking metrics are common SQL interview problems across companies such as Amazon and analytics-focused teams.

What data structure is used in Premier League Table Ranking?

The problem operates on tabular data stored in a relational table or DataFrame. The main concept is a window function over an ordered dataset rather than a traditional data structure like a hash map or tree.

What is the time complexity of Premier League Table Ranking?

The dominant operation is sorting the teams by ranking criteria, which takes O(n log n) time. After sorting, the window function assigns ranks in a single pass. Space complexity is typically O(n) for intermediate query results.

3246. Premier League Table Ranking - Practice Online

Table: TeamStats

+------------------+---------+
| Column Name      | Type    |
+------------------+---------+
| team_id          | int     |
| team_name        | varchar |
| matches_played   | int     |
| wins             | int     |
| draws            | int     |
| losses           | int     |
+------------------+---------+
team_id is the unique key for this table.
This table contains team id, team name, matches_played, wins, draws, and losses.

Write a solution to calculate the points and rank for each team in the league. Points are calculated as follows:

3 points for a win
1 point for a draw
0 points for a loss

Note: Teams with the same points must be assigned the same rank.

Return the result table ordered by points in descending, and then by team_name in ascending order.

The query result format is in the following example.

Example:

Input:

TeamStats table:

+---------+-----------------+----------------+------+-------+--------+
| team_id | team_name       | matches_played | wins | draws | losses |
+---------+-----------------+----------------+------+-------+--------+
| 1       | Manchester City | 10             | 6    | 2     | 2      |
| 2       | Liverpool       | 10             | 6    | 2     | 2      |
| 3       | Chelsea         | 10             | 5    | 3     | 2      |
| 4       | Arsenal         | 10             | 4    | 4     | 2      |
| 5       | Tottenham       | 10             | 3    | 5     | 2      |
+---------+-----------------+----------------+------+-------+--------+

Output:

+---------+-----------------+--------+----------+
| team_id | team_name       | points | position |
+---------+-----------------+--------+----------+
| 2       | Liverpool       | 20     | 1        |
| 1       | Manchester City | 20     | 1        |
| 3       | Chelsea         | 18     | 3        |
| 4       | Arsenal         | 16     | 4        |
| 5       | Tottenham       | 14     | 5        |
+---------+-----------------+--------+----------+

Explanation:

Manchester City and Liverpool both have 20 points (6 wins * 3 points + 2 draws * 1 point), so they share position 1.
Chelsea has 18 points (5 wins * 3 points + 3 draws * 1 point) and is position 3rd.
Arsenal has 16 points (4 wins * 3 points + 4 draws * 1 point) and is position 4th.
Tottenham has 14 points (3 wins * 3 points + 5 draws * 1 point) and is position 5th.

The output table is ordered by points in descending order, then by team_name in ascending order.