题目：

题解：

class Solution {public int[] maxNumber(int[] nums1, int[] nums2, int k) {int m = nums1.length, n = nums2.length;int[] maxSubsequence = new int[k];int start = Math.max(0, k - n), end = Math.min(k, m);for (int i = start; i <= end; i++) {int[] subsequence1 = maxSubsequence(nums1, i);int[] subsequence2 = maxSubsequence(nums2, k - i);int[] curMaxSubsequence = merge(subsequence1, subsequence2);if (compare(curMaxSubsequence, 0, maxSubsequence, 0) > 0) {System.arraycopy(curMaxSubsequence, 0, maxSubsequence, 0, k);}}return maxSubsequence;}public int[] maxSubsequence(int[] nums, int k) {int length = nums.length;int[] stack = new int[k];int top = -1;int remain = length - k;for (int i = 0; i < length; i++) {int num = nums[i];while (top >= 0 && stack[top] < num && remain > 0) {top--;remain--;}if (top < k - 1) {stack[++top] = num;} else {remain--;}}return stack;}public int[] merge(int[] subsequence1, int[] subsequence2) {int x = subsequence1.length, y = subsequence2.length;if (x == 0) {return subsequence2;}if (y == 0) {return subsequence1;}int mergeLength = x + y;int[] merged = new int[mergeLength];int index1 = 0, index2 = 0;for (int i = 0; i < mergeLength; i++) {if (compare(subsequence1, index1, subsequence2, index2) > 0) {merged[i] = subsequence1[index1++];} else {merged[i] = subsequence2[index2++];}}return merged;}public int compare(int[] subsequence1, int index1, int[] subsequence2, int index2) {int x = subsequence1.length, y = subsequence2.length;while (index1 < x && index2 < y) {int difference = subsequence1[index1] - subsequence2[index2];if (difference != 0) {return difference;}index1++;index2++;}return (x - index1) - (y - index2);}
}