<p>Given two integers <code>n</code> and <code>k</code>, return <em>the</em> <code>k<sup>th</sup></code> <em>lexicographically smallest integer in the range</em> <code>[1, n]</code>.</p>

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

<pre>
<strong>Input:</strong> n = 13, k = 2
<strong>Output:</strong> 10
<strong>Explanation:</strong> The lexicographical order is [1, 10, 11, 12, 13, 2, 3, 4, 5, 6, 7, 8, 9], so the second smallest number is 10.
</pre>

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

<pre>
<strong>Input:</strong> n = 1, k = 1
<strong>Output:</strong> 1
</pre>

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

<ul>
	<li><code>1 &lt;= k &lt;= n &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    int findKthNumber(int n, int k) {
            int x = 1; 
    
    while (k > 1) 
    {
        
        long count = 0; 
        
        for (long diff =1, cur=x; cur<=n; cur*= 10, diff*=10)
        {
            count += min(n - cur + 1, diff);
            
        }
        
        if (k > count)   
        {
            k = k - count;
            
            x++; 
         
        }
        else
        {
            k--;
            
            x *= 10; 
            
        }
        
    }
    
    return x; 
}
    
};
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