Given an integer array color_array of length n, where each element is either 0, 1, or 2, sort the array in-place so that all 0s appear first, followed by all 1s, then all 2s. Do not use built-in sorting functions. The sorting must be performed in-place.
Example 1
Input: [1,2,0,1,2,0]
Output: [0,0,1,1,2,2]
Explanation: All 0s are moved to the front, followed by 1s, then 2s.
Example 2
Input: [1,1,2,0,2]
Output: [0,1,1,2,2]
Explanation: All 0s are moved to the front, followed by 1s, then 2s.
Constraints
Case 1
Input: [2,2,1,0,0,1]
Expected: [0,0,1,1,2,2]
Case 2
Input: [0,1,2,0,1,2]
Expected: [0,0,1,1,2,2]
Case 3
Input: [2,1,0]
Expected: [0,1,2]
Case 4
Input: [1,0,2,2,1,0]
Expected: [0,0,1,1,2,2]
Case 5
Input: [0]
Expected: [0]