<p>You are given an integer <code>num</code>. You can swap two digits at most once to get the maximum valued number.</p>

<p>Return <em>the maximum valued number you can get</em>.</p>

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

<pre>
<strong>Input:</strong> num = 2736
<strong>Output:</strong> 7236
<strong>Explanation:</strong> Swap the number 2 and the number 7.
</pre>

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

<pre>
<strong>Input:</strong> num = 9973
<strong>Output:</strong> 9973
<strong>Explanation:</strong> No swap.
</pre>

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

<ul>
	<li><code>0 &lt;= num &lt;= 10<sup>8</sup></code></li>
</ul>

class Solution:
    def maximumSwap(self, num: int) -> int:
        num_list = list(str(num))
        last_occurrence = {int(digit): idx for idx, digit in enumerate(num_list)}

        # Traverse the list of digits
        for i in range(len(num_list)):
            # Check if there's a larger digit later in the number
            for d in range(9, int(num_list[i]), -1):
                if last_occurrence.get(d, -1) > i:
                    # Swap the current digit with the larger digit
                    num_list[i], num_list[last_occurrence[d]] = num_list[last_occurrence[d]], num_list[i]
                    return int(''.join(num_list))
        
        return int(''.join(num_list))

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