Leetcode Question 386 "Lexicographical Numbers" in Java

Given an integer n, return all the numbers in the range [1, n] sorted in lexicographical order. You must write an algorithm that runs in O(n) time and uses O(1) extra space. Example 1: Input: n = 13 Output: [1,10,11,12,13,2,3,4,5,6,7,8,9] Example 2: Input: n = 2 Output: [1,2]