题目：

题解：

class Solution {public List<Integer> lexicalOrder(int n) {List<Integer> ret = new ArrayList<Integer>();int number = 1;for (int i = 0; i < n; i++) {ret.add(number);if (number * 10 <= n) {number *= 10;} else {while (number % 10 == 9 || number + 1 > n) {number /= 10;}number++;}}return ret;}
}