Largest Positive Integer That Exists With Its Negative Python/Java solution

Most implementations store numbers in a set and check for -num while iterating. Python typically uses a built-in set, while Java uses HashSet. Both achieve O(n) time and O(n) space complexity.

What is the best approach for Largest Positive Integer That Exists With Its Negative?

The HashSet approach is the most efficient. Insert every number into a set, then check whether the opposite value (-num) exists. This allows constant-time lookups and solves the problem in O(n) time with O(n) space.

Is Largest Positive Integer That Exists With Its Negative asked at Google/Amazon/Meta?

Variants of this problem appear in interviews that test hash tables, array scanning, and pair detection logic. Companies such as Amazon, Google, and Meta commonly ask similar array and HashSet problems during early interview rounds.

What data structure is used in Largest Positive Integer That Exists With Its Negative?

A HashSet is the primary data structure used for the optimal solution. It provides O(1) average-time lookups, making it easy to check if both a number and its negative exist in the array.

What is the time complexity of Largest Positive Integer That Exists With Its Negative?

The optimal solution runs in O(n) time using a hash set to check whether both k and -k exist. A sorting-based alternative takes O(n log n) time due to the sorting step, followed by a linear scan.

Description Hints 2 Solution Video 6:20

2441. Largest Positive Integer That Exists With Its Negative

Q: Is Largest Positive Integer That Exists With Its Negative easy or hard?

The problem is classified as Easy on LeetCode with a high acceptance rate around 75%. It mainly tests basic array traversal and HashSet usage rather than complex algorithms.

Q: How to solve Largest Positive Integer That Exists With Its Negative in O(n)?

Store all numbers in a HashSet. Iterate through the array and check if the negative counterpart of each number exists in the set. Track the maximum positive value where both k and -k appear. Hash lookups make the overall complexity O(n).

Easy74.9% acceptance5 companies

Given an integer array nums that does not contain any zeros, find the largest positive integer k such that -k also exists in the array.

Return the positive integer k. If there is no such integer, return -1.

Example 1:

Input: nums = [-1,2,-3,3]
Output: 3
Explanation: 3 is the only valid k we can find in the array.

Example 2:

Input: nums = [-1,10,6,7,-7,1]
Output: 7
Explanation: Both 1 and 7 have their corresponding negative values in the array. 7 has a larger value.

Example 3:

Input: nums = [-10,8,6,7,-2,-3]
Output: -1
Explanation: There is no a single valid k, we return -1.

Constraints:

1 <= nums.length <= 1000
-1000 <= nums[i] <= 1000
nums[i] != 0

Asked at 5 companies

Coupang Microsoft

Google Amazon Bloomberg

Topics

Hints open one at a time

Hint 1

What data structure can help you to determine if an element exists?

Hint 2

Would a hash table help?

6:20

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