<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:
    vector<int> numsSameConsecDiff(int n, int k) {
        vector<vector<int>> v = {{0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}, {8}, {9}};
        n--;
        int tens = 10;
        while(n){
            vector<vector<int>> vNext(10);
            for(int i = 0; i < 10; i++){
                if(i - k >= 0){
                    for(auto x : v[i - k]) vNext[i].push_back(x + tens * i);
                }
                if(k && i + k < 10){
                    for(auto x : v[i + k]) vNext[i].push_back(x + tens * i);
                }
            }
            v = vNext;
            tens *= 10;
            n--;
        }
        vector<int> ret;
        for(int i = 1; i < 10; i++) ret.insert(end(ret), v[i].begin(), v[i].end());
        return ret;
    }
};
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