You are given an integer array `digits`, where each element is a digit. The array may contain duplicates.

You need to find all the unique integers that follow the given requirements:

- The integer consists of the concatenation of three elements from `digits` in any arbitrary order.
- The integer does not have leading zeros.
- The integer is even.

For example, if the given `digits` were `[1, 2, 3]`, integers `132` and `312` follow the requirements.

Return a sorted array of the unique integers.

Example 1:

    Input: digits = [2,1,3,0]
    Output: [102,120,130,132,210,230,302,310,312,320]
    Explanation: All the possible integers that follow the requirements are in the output array.
    Notice that there are no odd integers or integers with leading zeros.

Example 2:

    Input: digits = [2,2,8,8,2]
    Output: [222,228,282,288,822,828,882]
    Explanation: The same digit can be used as many times as it appears in digits.
    In this example, the digit 8 is used twice each time in 288, 828, and 882.

Example 3:

    Input: digits = [3,7,5]
    Output: []
    Explanation: No even integers can be formed using the given digits.

Constraints:

- `3 <= digits.length <= 100`
- `0 <= digits[i] <= 9`