Given a number s(in string form). Find the Smallest number (Not leading Zeros) which can be obtained by rearranging the digits of given number.
 

Example 1:

Input: s = "846903"
Output: 304688
Explanation: 304689 is the smallest number
by rearranging the digits.

Example 2:

Input: s = "55010"
Output: 10055
Explanation: 10055 is the smallest number 
by rearranging the digts.

Your Task:
You don't need to read or print anything. Your task is to complete the function minimum_number() which takes the number as input parameter and returns the smallest number than can be formed without leading zeros by rearranging the digits of the number.
 

Expected Time Complexity: O(N * log(N)) where N is the number of digits of the given number
Expected Space Complexity: O(1)
 

Constraints:
1 <= N <= 10⁵