File: kids-with-the-greatest-number-of-candies/solution.py

Date: 2026-06-06

Time: 17:11

kids-with-the-greatest-number-of-candies/solution.py

Purpose

Solves LeetCode 1431 — Kids With the Greatest Number of Candies. Given a list of candy counts per kid and a number of extra candies, determine which kids would have the maximum (or tied-for-maximum) count if they alone received all the extra candies.

Key Components

Solution.kidsWithCandies(candies, extraCandies) -> List[bool] — the single method. Contract:

• Input: candies is a non-empty list of non-negative ints; extraCandies is a non-negative int.
• Output: A boolean list of the same length, where result[i] is True iff candies[i] + extraCandies >= max(candies).

Patterns

• Precompute-then-sweep: Computes max_candies once in O(n), then builds the result in a single list comprehension — also O(n). This avoids the naive O(n^2) approach of calling max() inside the loop.
• LeetCode class convention: Wraps the solution in a Solution class with a specifically-named method, matching the LeetCode submission interface used across this entire repo.

Dependencies

• Imports: List from typing — used only for the type annotation. No runtime dependency beyond the standard library.
• Imported by: kids-with-the-greatest-number-of-candies/test_solution.py imports this Solution class. The long "Imported By" list in the prompt is an artifact of the tooling — those test files import their own local Solution, not this one.

Flow

1. max(candies) scans the full list to find the current global maximum.

2. The list comprehension iterates each kid's count c, checks if c + extraCandies meets or exceeds that maximum, and collects the booleans.

3. Returns the result directly — no mutation of input.

Invariants

• len(result) == len(candies) — output is always index-aligned with input.
• The comparison is >=, not > — a kid who already has the max (without extra candies) always gets True.
• max(candies) will raise ValueError on an empty list; the problem guarantees n >= 2, so this is never hit under valid input.

Error Handling

None. The function trusts its caller to provide valid input per the problem constraints. An empty candies list would propagate a ValueError from max().

Topics to Explore

• [file] kids-with-the-greatest-number-of-candies/test_solution.py — See which edge cases the tests cover (all-equal, single kid at max, etc.)
• [file] kids-with-the-greatest-number-of-candies/review.md — Code review notes may flag alternative approaches or complexity analysis
• [function] distribute-candies/solution.py:Solution.distributeCandies — Another candy-themed problem; compare how a set-based approach differs from this threshold check
• [general] list-comprehension-vs-map — Whether the repo consistently uses comprehensions or mixes in map()/filter() across solutions

Beliefs

• kids-candies-linear-time — kidsWithCandies runs in O(n) time and O(n) space, making exactly two passes over the input (one for max, one for the comprehension).
• kids-candies-gte-not-gt — The comparison uses >=, so a kid already at the global max always returns True regardless of extraCandies.
• kids-candies-no-mutation — The function never modifies the input candies list; it returns a new list.
• kids-candies-empty-input-crashes — Passing an empty list raises ValueError from max(); the problem constraints prevent this.