lexicographical-numbers

Posted 2020-08-04 笨鸟居士的博客

https://leetcode.com/problems/lexicographical-numbers/

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