Abstract / Summary

Given arrays of candies and extra candies each kid has, find the minimum extra candies needed so some kids can have the highest number of candies.

Note

The full problem description, including helpful examples, can be found on LeetCode.

This problem is ranked as

and has an acceptance rate of about 88% (1+ million submissions).

Typical patterns to solve this problem:

• Array

Every single line of code was written by me, 100% from scratch, between August 2023 and August 2024.
However, two years later I set up this website and used various AI tools to generate most of the walkthrough / explanations below.

See this dedicated page for more details.

Overview

The provided implementation defines a single method kidsWithCandies inside a class Solution. The method receives a list of integers representing the current number of candies each child has and an integer extraCandies that can be added to any child’s count. It returns a list of boolean values indicating, for each child, whether that child can reach or exceed the highest candy count among all children after receiving the extra candies.

Key Steps

The core logic is expressed in a single list comprehension that builds the result list. The comprehension iterates over each element i in the input list candies, adds the extraCandies value, and compares the sum to the maximum value found in the original candies list.

return [ i + extraCandies >= max(candies) for i in candies ]

The expression i + extraCandies >= max(candies) evaluates to True when the child’s new total meets or surpasses the current highest total, and False otherwise. The list comprehension aggregates these boolean outcomes in the order of the original list, preserving positional correspondence between input children and output flags.

Edge Cases

The implementation naturally accommodates several boundary conditions:

When extraCandies is zero, the comparison reduces to checking whether each child already possesses the maximum number of candies. The result will be True only for those children whose count equals the maximum.

If extraCandies is negative, the addition effectively reduces each child’s count before the comparison. The code still correctly determines whether the reduced total can meet or exceed the original maximum, handling scenarios where a penalty or loss of candies is modeled.

When all elements in candies are identical, the maximum value equals every element. Adding any non-negative extraCandies will cause every comparison to succeed, yielding a list of all True. Conversely, a negative extraCandies that does not drop any child below the shared maximum will still produce all True.

The function works for a single-element list as well. In that case, the maximum is the sole element, and the comparison determines whether that single child can meet or exceed its own count after the adjustment, resulting in a list containing a single boolean value.

Performance Optimizations

The code leverages Python’s built-in max function, which is implemented in C and provides fast traversal of the input list to locate the greatest value. By using a list comprehension, the implementation benefits from the interpreter’s optimized loop construct, reducing overhead compared to an explicit for loop with manual list appends.

Because the result list is constructed in a single expression, memory allocation occurs only once for the final list, avoiding repeated resizing that could happen with incremental appends. The use of a boolean expression directly inside the comprehension eliminates the need for auxiliary variables, keeping the execution path tight and cache-friendly.

Imagine a group of friends who each have a little pile of candies in front of them. Some friends have lots of treats, and some have just a few. There is a big bag of extra candies nearby. The goal is to see which children would end up having the most candies if they were given all the treats from that extra bag.

To figure this out, this code looks at each child one by one. For every child, it imagines giving them all the extra candies. It then checks if that total amount is as high as, or even higher than, the pile belonging to the child who currently has the absolute most candies in the whole group. If adding those extra candies makes the pile big enough to be the largest, the code makes a little note that says yes for that child. If the pile is still smaller than the biggest one, the code makes a note that says no. It does this for every single friend until it has a final list of answers for everyone.

Several LLMs ranked my code quality on a scale from 1 (very poor) to 10 (outstanding):

not analyzed yet

I wrote a basic crawler to find other solutions to that problem.
Obviously, I did that after I solved the problem myself.

In general, AlgoMonster and WalkCCC solutions are high-quality and always worth a look.
I haven't checked most of the other solutions, but they might be helpful as well.

And of course, the LeetCode forum is always a good place (or even the best) to look for alternative approaches.

(click on a column header to sort the table)

	author
author	solutions
www	AlgoMonster	C++	Python	Java								TS
	WalkCCC	C++	Python	Java
	leetcode.ca	C++	Python	Java				Go	C	PHP	Rust	TS
	Progiez	C++	Python	Java
github	BigEggStudy					C#
	black-shadows	C++
	chandansgowda		Python
	charles-wangkai			Java
	DimitrisJim								C
	everthis				JS
	fartem						Ruby
	fpdjsns	C++
	fsq	C++
	JoshCrozier				JS
	keineahnung2345	C++
	Krazune	C++
	lkwq007		Python
	muhammadfarhankt							Go
	suxrobGM					C#
	varunu28			Java
	vthwang			Java
	YuriSpiridonov		Python
AlgoMonster	C++, Python, Java, TypeScript
WalkCCC	C++, Python, Java
leetcode.ca	C, C++, Go, Java, PHP, Python, Rust, TypeScript
Progiez	C++, Java, Python
BigEggStudy	C#
black-shadows	C++, C++
chandansgowda	Python
charles-wangkai	Java
DimitrisJim	C
everthis	JavaScript
fartem	Ruby
fpdjsns	C++
fsq	C++
JoshCrozier	JavaScript
keineahnung2345	C++
Krazune	C++
lkwq007	Python
muhammadfarhankt	Go
suxrobGM	C#
varunu28	Java
vthwang	Java
YuriSpiridonov	Python

There are a few extra pages giving you some insights into my setup:

• Tech Stack - my development environment and tools
• AI - how AI helped me create this website (NOT solving the problems)
• Progress - progression over time
• Quality - code quality