LeetCode[386] 字典序排数

https://leetcode.cn/problems/lexicographical-numbers/description/

想像成一颗树的遍历

AC代码：

class Solution {
public:
    vector<int> lexicalOrder(int n) {
        int cur = 1;
        vector<int> ans(n);
        for (int i = 0; i < n; i++)
        {
            ans[i] = cur;
            if (cur * 10 <= n) {
                cur *= 10;
            }else {
                while (cur == n || cur%10 == 9) {
                    cur /= 10;
                }
                cur++;
            }
        }
        return ans;   
    }
};