Given two arrays of length m and n with digits 0-9 representing two numbers. Create the maximum number of length k <= m + n from digits of the two. The relative order of the digits from the same array must be preserved. Return an array of the k digits. You should try to optimize your time and space complexity.

public class Solution {
    public int[] maxNumber(int[] nums1, int[] nums2, int k) {
        int[] result = new int[k];
        for (int i = Math.max(0, k - nums2.length); i <= nums1.length && i <= k; i++) {
            int[] candidate = merge(maxArr(nums1, i), maxArr(nums2, k - i), k);
            if (greater(candidate, 0, result, 0)) {
                result = candidate;
            }
        }
        return result;
    }

    public int[] maxArr(int[] nums, int k) {
        int[] result = new int[k];
        for (int i = 0, j = 0; i < nums.length; i++) {
            while (nums.length - i + j > k && j > 0 && result[j - 1] < nums[i]) {
                j--;
            }
            if (j < k) {
                result[j++] = nums[i];
            }
        }
        return result;
    }

    public boolean greater(int[] nums1, int i, int[] nums2, int j) {
        while (i < nums1.length && j < nums2.length && nums1[i] == nums2[j]) {
            i++;
            j++;
        }
        return j == nums2.length || (i < nums1.length && nums1[i] > nums2[j]);
    }
    public int[] merge(int[] nums1, int[] nums2, int k) {
        int[] result = new int[k];
        for (int i = 0, j = 0, l = 0; l < k; l++) {
            result[l] = greater(nums1, i, nums2, j) ? nums1[i++] : nums2[j++];
        }
        return result;
    }
}