<p>Given two integers n and k, return <em>an array of all the integers of length </em><code>n</code><em> where the difference between every two consecutive digits is </em><code>k</code>. You may return the answer in <strong>any order</strong>.</p>

<p>Note that the integers should not have leading zeros. Integers as <code>02</code> and <code>043</code> are not allowed.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> n = 3, k = 7
<strong>Output:</strong> [181,292,707,818,929]
<strong>Explanation:</strong> Note that 070 is not a valid number, because it has leading zeroes.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> n = 2, k = 1
<strong>Output:</strong> [10,12,21,23,32,34,43,45,54,56,65,67,76,78,87,89,98]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>2 &lt;= n &lt;= 9</code></li>
	<li><code>0 &lt;= k &lt;= 9</code></li>
</ul>

class Solution {
public:
    void solve(vector<int>& nums, vector<vector<int>>& ans, vector<int> db, int ind, int n, int k) {
        if (db.size() == n) { 
            ans.push_back(db);
            return;
        }

        for (int i = 0; i < nums.size(); i++) {  
            if (db.empty() && nums[i] == 0) 
            continue;
            if (db.empty() || abs(db.back() - nums[i]) == k) {
                db.push_back(nums[i]);
                solve(nums, ans, db, ind + 1, n, k); 
                db.pop_back();
            }
        }
    }

    vector<int> numsSameConsecDiff(int n, int k) {
        vector<int> nums(10);
        for (int i = 0; i < 10; i++) {
            nums[i] = i;
        }

        vector<vector<int>> ans; 
        vector<int> db;

        solve(nums, ans, db, 0, n, k);

        vector<int> result;
        
        for (const auto& seq : ans) {
            int num = 0;
            for (int digit : seq) {
                num = num * 10 + digit;
            }
            result.push_back(num);
        }

        return result;
    }
};

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