Скачать или смотреть N-Repeated Element in Size 2N Array 🔥 | LeetCode 961 | Easy

In this video, we solve LeetCode 961 — N-Repeated Element in Size 2N Array using two different approaches.

Code:
https://leetcode.com/problems/n-repea...

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You are given an integer array nums of length 2n where:

There are n + 1 unique elements.

Exactly one element is repeated n times.


Your task is to return the element that is repeated n times.

🔗 Problem Link:
https://leetcode.com/problems/n-repea...


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✅ Approach 1 — O(1) Space using Constraints

Since the constraints guarantee that values are within a fixed small range, we:

Create a fixed-size frequency array.

Traverse the array and increment the count.

The first element whose frequency becomes greater than 1 is the answer.


Time Complexity: O(n)
Space Complexity: O(1) (constant extra space due to fixed-size array)


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✅ Approach 2 — Using HashSet

Use a HashSet to track visited numbers.

Traverse the array.

If a number is already present in the set, return it immediately.


Time Complexity: O(n)
Space Complexity: O(n)


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