31: Find array duplicates
Given an array
of integers, from 1
to array.Length
inclusive. Some array items appear twice
and others appear once
. Find all duplicates. The result should be in ascending order
Note: Solve without extra space and in
O(n)
runtime
Example 1
Input: [3, 2, 1, 3]
Output: [3]
Example 2
Input: [3, 2, 1, 3, 2]
Output: [2, 3]