An integer x is numerically balanced if for every digit d in the number x, there are exactly d occurrences of that digit in x.

Given an integer n, return the smallest numerically balanced number strictly greater than n.

Example 1:

Input: n = 1
Output: 22
Explanation:
22 is numerically balanced since:
- The digit 2 occurs 2 times.
It is also the smallest numerically balanced number strictly greater than 1.


Example 2:

Input: n = 1000
Output: 1333
Explanation:
1333 is numerically balanced since:
- The digit 1 occurs 1 time.
- The digit 3 occurs 3 times.
It is also the smallest numerically balanced number strictly greater than 1000.
Note that 1022 cannot be the answer because 0 appeared more than 0 times.


Example 3:

Input: n = 3000
Output: 3133
Explanation:
3133 is numerically balanced since:
- The digit 1 occurs 1 time.
- The digit 3 occurs 3 times.
It is also the smallest numerically balanced number strictly greater than 3000.


Constraints:

• 0 <= n <= 106

## Solution: Permutation

Time complexity: O(log(n)!)
Space complexity: O(log(n)) ?

## C++

If you like my articles / videos, donations are welcome.

Buy anything from Amazon to support our website

Paypal
Venmo
huahualeetcode