<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:
        s = list(str(num))

        if len(s) <= 1:
            return num

        i = 1
        while i < len(s):
            if s[i-1] < s[i]:
                break
            i += 1
        if i == len(s):
            return num
        maxRight, maxIdx = s[i], i
        minIdx, j = i-1, i-1
        i += 1
        while i < len(s):
            if s[i] >= maxRight:
                maxRight = s[i]
                maxIdx = i
            i += 1
        while j > -1:
            if s[j] < maxRight:
                minIdx = j
            j -= 1
        s[minIdx], s[maxIdx] = s[maxIdx], s[minIdx]

        return int(''.join(s))
16400