<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) {
        set<int> ans;
        queue<string> q;
        for(int i=1;i<=9;i++){
            q.push(to_string(i));
            while(!q.empty()){
                string str=q.front(); q.pop();
                if(str.size()==n){
                    int num = stoi(str);
                    ans.insert(num);
                    //break;
                }
                else if(str.size()<n){
                    int dig = str.back() - '0';
                    if(dig-k>=0){
                        char next = (dig-k) + '0';
                        str.push_back(next); q.push(str);
                        str.pop_back();
                    }
                    if(dig+k<=9){
                        char next = (dig+k) + '0';
                        str.push_back(next); q.push(str);
                        str.pop_back();
                    }
                }
            }
            q.empty();
        }
        vector<int> res;
        for(auto x:ans) res.push_back(x);
        return res;
    }
};
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