Smallest Value of the Rearranged Number
<p>You are given an integer <code>num.</code> <strong>Rearrange</strong> the digits of <code>num</code> such that its value is <strong>minimized</strong> and it does not contain <strong>any</strong> leading zeros.</p>

<p>Return <em>the rearranged number with minimal value</em>.</p>

<p>Note that the sign of the number does not change after rearranging the digits.</p>

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

<pre>
<strong>Input:</strong> num = 310
<strong>Output:</strong> 103
<strong>Explanation:</strong> The possible arrangements for the digits of 310 are 013, 031, 103, 130, 301, 310. 
The arrangement with the smallest value that does not contain any leading zeros is 103.
</pre>

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

<pre>
<strong>Input:</strong> num = -7605
<strong>Output:</strong> -7650
<strong>Explanation:</strong> Some possible arrangements for the digits of -7605 are -7650, -6705, -5076, -0567.
The arrangement with the smallest value that does not contain any leading zeros is -7650.
</pre>

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

<ul>
	<li><code>-10<sup>15</sup> &lt;= num &lt;= 10<sup>15</sup></code></li>
</ul>
Math; Sorting
class Solution:
    def smallestNumber(self, num: int) -> int:
        neg = num < 0
        num = abs(num)
        cnt = [0] * 10
        while num:
            cnt[num % 10] += 1
            num //= 10
        ans = 0
        if neg:
            for i in reversed(range(10)):
                for _ in range(cnt[i]):
                    ans *= 10
                    ans += i
            return -ans
        if cnt[0]:
            for i in range(1, 10):
                if cnt[i]:
                    ans = i
                    cnt[i] -= 1
                    break
        for i in range(10):
            for _ in range(cnt[i]):
                ans *= 10
                ans += i
        return ans
