In-place Array Reordering (0/1/2 sort variant)

Given an integer array nums containing only 0, 1, and 2, sort the array in-place so that elements of the same value are adjacent, in the order 0, then 1, then 2. Requirements: Must be in-place with only O(1) extra space. Target time complexity: O(n). Input Format Line 1: integer n Line 2: n integers (each is 0/1/2) representing nums Output Format Print the sorted array on one line, space-separated. Constraints 1 <= n <= 2 * 10^5 Example Input 6 2 0 2 1 1 0 Output 0 0 1 1 2 2