Leetcode #2600: K Items With the Maximum Sum
In this guide, we solve Leetcode #2600 K Items With the Maximum Sum in Python and focus on the core idea that makes the solution efficient.
You will see the intuition, the step-by-step method, and a clean Python implementation you can use in interviews.
Problem Statement
There is a bag that consists of items, each item has a number 1, 0, or -1 written on it. You are given four non-negative integers numOnes, numZeros, numNegOnes, and k.
Quick Facts
- Difficulty: Easy
- Premium: No
- Tags: Greedy, Math
Intuition
A locally optimal choice leads to a globally optimal result for this structure.
That means we can commit to decisions as we scan without backtracking.
Approach
Sort or preprocess if needed, then repeatedly take the best available local choice.
Maintain the minimal state necessary to validate the greedy decision.
Steps:
- Sort or preprocess as needed.
- Iterate and pick the best local option.
- Track the current solution.
Example
Input: numOnes = 3, numZeros = 2, numNegOnes = 0, k = 2
Output: 2
Explanation: We have a bag of items with numbers written on them {1, 1, 1, 0, 0}. We take 2 items with 1 written on them and get a sum in a total of 2.
It can be proven that 2 is the maximum possible sum.
Python Solution
class Solution:
def kItemsWithMaximumSum(
self, numOnes: int, numZeros: int, numNegOnes: int, k: int
) -> int:
if numOnes >= k:
return k
if numZeros >= k - numOnes:
return numOnes
return numOnes - (k - numOnes - numZeros)
Complexity
The time complexity is , and the space complexity is . The space complexity is .
Edge Cases and Pitfalls
Watch for boundary values, empty inputs, and duplicate values where applicable. If the problem involves ordering or constraints, confirm the invariant is preserved at every step.
Summary
This Python solution focuses on the essential structure of the problem and keeps the implementation interview-friendly while meeting the constraints.