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Problem solution · SQL

Rectangles Area

Rectangles Area: a SQL solution using relational aggregation. Learn the idea, check the complexity, and read the full code, with credit to walkccc LeetCode Solutions.

Technique
Relational aggregation
Source
walkccc LeetCode Solutions
Length
11 lines
Start with the idea.

Try the problem first. If you get stuck, read the approach below, then write your own solution. The full code is at the bottom.

Approach

Relational aggregation

For Rectangles Area, the query transforms and combines relational rows, then filters or aggregates them into the requested result.

  1. Identify the source rows and join keys.
  2. Apply filters before aggregation when possible.
  3. Group, rank, or project the final columns required by the result.

Code notes

  • 11 lines of SQL from the credited upstream file 1459.sql.
  • The implementation keeps its working state in language-native values and containers.
  • No explicit loop blocks detected.

Complexity

Review join cardinality, grouping keys, and available indexes when estimating query cost.

Check the problem constraints before deciding whether this complexity will pass.

Source

Code and credit

This code comes from walkccc LeetCode Solutions by P.-Y. Chen (walkccc) and is used under the MIT licence.

Open problem ↗Original source ↗
Full codeRectangles Area · SQLSQL
Use this to learn the idea, then write your own version.
SELECT  P1.id AS p1,  P2.id AS p2,  ABS(p1.x_value - p2.x_value) * ABS(p1.y_value - p2.y_value) AS areaFROM Points AS P1, Points AS P2WHERE  P1.id < P2.id  AND P1.x_value != P2.x_value  AND P1.y_value != P2.y_valueORDER BY area DESC, p1, p2;

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