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LESSON 365 OF 678 · HASH TABLE

Find Duplicates in Array

Practice O(n)

Given an array of integers, return a new array containing only the duplicates.

The resulting array's values can be stored in any order.

Example:

Input: [2, 3, 1, 1, 4, 3, 2, 1]
Output: [2, 1, 3]
			

Note:

Your algorithm should run in O(n) time and use O(n) extra space.


STEP 1 OF 7
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