<p>Given two strings <code>s</code> and <code>t</code>, transform string <code>s</code> into string <code>t</code> using the following operation any number of times:</p>

<ul>
	<li>Choose a <strong>non-empty</strong> substring in <code>s</code> and sort it in place so the characters are in <strong>ascending order</strong>.

	<ul>
		<li>For example, applying the operation on the underlined substring in <code>&quot;1<u>4234</u>&quot;</code> results in <code>&quot;1<u>2344</u>&quot;</code>.</li>
	</ul>
	</li>
</ul>

<p>Return <code>true</code> if <em>it is possible to transform <code>s</code> into <code>t</code></em>. Otherwise, return <code>false</code>.</p>

<p>A <strong>substring</strong> is a contiguous sequence of characters within a string.</p>

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

<pre>
<strong>Input:</strong> s = &quot;84532&quot;, t = &quot;34852&quot;
<strong>Output:</strong> true
<strong>Explanation:</strong> You can transform s into t using the following sort operations:
&quot;84<u>53</u>2&quot; (from index 2 to 3) -&gt; &quot;84<u>35</u>2&quot;
&quot;<u>843</u>52&quot; (from index 0 to 2) -&gt; &quot;<u>348</u>52&quot;
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;34521&quot;, t = &quot;23415&quot;
<strong>Output:</strong> true
<strong>Explanation:</strong> You can transform s into t using the following sort operations:
&quot;<u>3452</u>1&quot; -&gt; &quot;<u>2345</u>1&quot;
&quot;234<u>51</u>&quot; -&gt; &quot;234<u>15</u>&quot;
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;12345&quot;, t = &quot;12435&quot;
<strong>Output:</strong> false
</pre>

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

<ul>
	<li><code>s.length == t.length</code></li>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s</code> and <code>t</code> consist of only digits.</li>
</ul>

from collections import deque

class Solution:
    def isTransformable(self, source: str, target: str) -> bool:
        def count_digits(s: str) -> list[int]:
            digit_count = [0] * 10
            for char in s:
                digit_count[int(char)] += 1
            return digit_count
        
        if count_digits(source) != count_digits(target):
            return False
        
        # Initialize position deques for each digit
        digit_positions = [deque() for _ in range(10)]
        for index, char in enumerate(source):
            digit_positions[int(char)].append(index)
        
        # For each digit in `target`, check if we can place this digit from `source` at
        # the same position as in `target`. Ensure that all the left digits are equal to
        # or greater than it. This is because the only operation we can perform
        # is sorting in ascending order. If there is a digit to the left that is
        # smaller than it, we can never move it to the same position as in `target`.
        # However, if all the digits to its left are equal to or greater than it,
        # we can move it one position to the left until it reaches the same position
        # as in `target`.
        for char in target:
            digit = int(char)
            position = digit_positions[digit].popleft()
            for smaller_digit in range(digit):
                if digit_positions[smaller_digit] and digit_positions[smaller_digit][0] < position:
                    return False
        
        return True

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