File: convert-the-temperature/solution.py

Date: 2026-06-06

Time: 15:54

convert-the-temperature/solution.py

Purpose

This file solves LeetCode 2469 — Convert the Temperature. It owns a single responsibility: given a Celsius value, return the equivalent Kelvin and Fahrenheit values as a two-element list. It's one of ~400+ solution files in the repo, each following the same Solution class convention.

Key Components

Solution.convert_temperature(celsius: float) -> list[float] — the only method. It applies two standard physics formulas inline:

• Kelvin: celsius + 273.15 (absolute zero offset)
• Fahrenheit: celsius * 1.80 + 32.00 (linear scale conversion)

Returns [kelvin, fahrenheit] — ordering matters, it matches LeetCode's expected output contract.

Patterns

• Single-method Solution class: standard LeetCode scaffold. Every problem in this repo follows this pattern — a class named Solution with one public method matching the problem's function signature.
• Pure computation, no mutation: the method is stateless. No side effects, no instance state, no imports.
• Direct return expression: no intermediate variables. The computation is simple enough that a single return statement is clearer than named locals.

Dependencies

Imports: None. The solution uses only built-in arithmetic.

Imported by: The "Imported By" list in the prompt is misleading — those are *all* test files across the entire repo, not files that specifically import this solution. The actual consumer is convert-the-temperature/test_solution.py, which imports this Solution class to verify its behavior.

Flow

1. Caller passes celsius (a float).

2. Two arithmetic expressions are evaluated left-to-right inside the list literal.

3. A two-element list[float] is returned. No branching, no loops.

Invariants

• Input range: the docstring documents 0 <= celsius <= 1000 (the LeetCode constraint), but the code doesn't enforce it — it's a pure formula that works for any float.
• Output ordering: Kelvin is always index 0, Fahrenheit is always index 1. Swapping would break the LeetCode judge and any test that asserts on position.
• Precision: uses float literals 273.15, 1.80, 32.00. The .00 suffixes on 1.80 and 32.00 are cosmetic — they don't change float precision, but they signal intent that these are exact decimal values from the conversion formula.

Error Handling

None. No validation, no try/except, no edge-case guards. This is appropriate — the LeetCode contract guarantees valid input, and the arithmetic can't fail for any float value (no division, no overflow risk within the stated range).

Topics to Explore

• [file] convert-the-temperature/test_solution.py — See which edge cases (0, 1000, fractional values) the test suite covers
• [file] convert-the-temperature/review.md — The code review notes may flag precision concerns or alternative approaches
• [general] solution-class-convention — How all 400+ solutions share the same Solution class pattern and how the test harness discovers them
• [file] run_tests.py — The test runner that orchestrates execution across all solution directories

Beliefs

• kelvin-is-index-zero — convert_temperature always returns Kelvin at index 0 and Fahrenheit at index 1; reversing the order breaks the LeetCode contract
• no-input-validation — The method performs no bounds checking on celsius; it relies on the caller (LeetCode judge) to provide values in [0, 1000]
• stateless-pure-function — convert_temperature uses no instance state, no imports, and no side effects — it's a pure function attached to a class solely for LeetCode compatibility
• fahrenheit-formula-uses-multiplication — The Fahrenheit conversion uses celsius * 1.80 + 32.00, which is equivalent to celsius * 9/5 + 32 but avoids integer division