<p>Given an integer array <code>queries</code> and a <strong>positive</strong> integer <code>intLength</code>, return <em>an array</em> <code>answer</code> <em>where</em> <code>answer[i]</code> <em>is either the </em><code>queries[i]<sup>th</sup></code> <em>smallest <strong>positive palindrome</strong> of length</em> <code>intLength</code> <em>or</em> <code>-1</code><em> if no such palindrome exists</em>.</p>

<p>A <strong>palindrome</strong> is a number that reads the same backwards and forwards. Palindromes cannot have leading zeros.</p>

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

<pre>
<strong>Input:</strong> queries = [1,2,3,4,5,90], intLength = 3
<strong>Output:</strong> [101,111,121,131,141,999]
<strong>Explanation:</strong>
The first few palindromes of length 3 are:
101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, ...
The 90<sup>th</sup> palindrome of length 3 is 999.
</pre>

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

<pre>
<strong>Input:</strong> queries = [2,4,6], intLength = 4
<strong>Output:</strong> [1111,1331,1551]
<strong>Explanation:</strong>
The first six palindromes of length 4 are:
1001, 1111, 1221, 1331, 1441, and 1551.
</pre>

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

<ul>
	<li><code>1 &lt;= queries.length &lt;= 5 * 10<sup>4</sup></code></li>
	<li><code>1 &lt;= queries[i] &lt;= 10<sup>9</sup></code></li>
	<li><code>1 &lt;= intLength&nbsp;&lt;= 15</code></li>
</ul>

class Solution {
public:

    long long solve(string s){
        long long ans=0;
        for(long long i=0;i<s.length();i++)  ans+=(s[i]-'0')*(pow(10,s.length()-i-1));
        return ans;
    }
    vector<long long> kthPalindrome(vector<int>& queries, int intLength) {
        int n=queries.size();
        long long mid=(intLength-1)/2;
        vector<long long>ans;
        for(int i=0;i<n;i++){
            long long pos=queries[i];
            string s="";
            for(int i=0;i<intLength;i++){
                s+="0";
            }
            s[0]='1';
            s[intLength-1]='1';
            bool flag=0;
            for(long long i=0;i<=mid;i++){
                 long long curr_palind=pow(10,mid-i);
                //  cout<<curr_palind<<endl;
                if((i>0&&pos>10*curr_palind)||(i==0&&pos>9*curr_palind)){
                    flag=1;
                    ans.push_back(-1);
                    break;
                }
                 if(pos>=curr_palind){
                 if(i==0){
                     s[i]=(ceil((float)pos/(float)curr_palind))+'0';
                     pos-=(s[i]-'0'-1)*curr_palind;
                     s[intLength-i-1]=s[i];
                 }
                 else{
                    s[i]=(ceil((float)pos/(float)curr_palind))-1+'0';
                    pos-=(s[i]-'0')*curr_palind;
                    s[intLength-i-1]=s[i];
                 }
                //   cout<<s[i]<<" ";
                //   s[intLength-i-1]=s[i];
                 
                 }
                 if(pos<0) break;
                //  cout<<pos<<endl;
            }
            if(flag==0)
            ans.push_back(solve(s));

        }
        return ans;
        // return {};
    }
};
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