<p>An integer has <strong>monotone increasing digits</strong> if and only if each pair of adjacent digits <code>x</code> and <code>y</code> satisfy <code>x &lt;= y</code>.</p>

<p>Given an integer <code>n</code>, return <em>the largest number that is less than or equal to </em><code>n</code><em> with <strong>monotone increasing digits</strong></em>.</p>

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

<pre>
<strong>Input:</strong> n = 10
<strong>Output:</strong> 9
</pre>

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

<pre>
<strong>Input:</strong> n = 1234
<strong>Output:</strong> 1234
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> n = 332
<strong>Output:</strong> 299
</pre>

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

<ul>
	<li><code>0 &lt;= n &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution:
    def monotoneIncreasingDigits(self, n: int) -> int:
        digits = list(str(n))
        n = len(digits)
        idx_to_modify = n

        for i in range(n - 1, 0, -1):
            if digits[i] < digits[i - 1]:
                idx_to_modify = i
                digits[i - 1] = str(int(digits[i - 1]) - 1)
        
        for i in range(idx_to_modify, n):
            digits[i] = '9'

        return int("".join(digits))
16500