<p>Given an integer <code>n</code>, return the <code>n<sup>th</sup></code> digit of the infinite integer sequence <code>[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ...]</code>.</p>

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

<pre>
<strong>Input:</strong> n = 3
<strong>Output:</strong> 3
</pre>

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

<pre>
<strong>Input:</strong> n = 11
<strong>Output:</strong> 0
<strong>Explanation:</strong> The 11<sup>th</sup> digit of the sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... is a 0, which is part of the number 10.
</pre>

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

<ul>
	<li><code>1 &lt;= n &lt;= 2<sup>31</sup> - 1</code></li>
</ul>

class Solution {
public:
    int findNthDigit(int n) 
    {
        long long digit = 9;
        int first = 1;
        int length = 1;
        while(n>digit*length)
        {
            n = n - digit*length;
            length++;
            first = first * 10;
            digit = digit * 10;
        }
        first = first + (n - 1)/length;
        string str = to_string(first);
        return str[(n - 1)%length] - '0';
    }
};
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