// Find All Duplicates in an Array — EASY

// Category: array

Given an integer array `nums` of length `n` where all integers are in the range `[1, n]`, some elements appear **twice** and others appear **once**.

Return an array of all elements that appear **twice**, sorted in ascending order.

**Constraints:**

- `n == nums.length`

Example: nums = [4,3,2,7,8,2,3,1]

Output: [2,3]