Find smallest permutation under constraints

Given a non-negative integer `n`, consider its decimal digits as a multiset (digits can repeat). 1) Return the **smallest possible integer** that can be formed by rearranging the digits of `n`, **allowing leading zeros** (i.e., you are allowed to place `0` at the front; the result is still treated as an integer value). 2) Follow-up: Given an additional integer `lowerBound`, return the **smallest integer strictly greater than `lowerBound`** that can be formed by rearranging the digits of `n`. If no such number exists, return an indication such as `-1`. ### Example - `n = 178`: smallest permutation (allow leading zeros) is `178`. - Follow-up: `n = 178`, `lowerBound = 200` → answer is `718`. ### Constraints - You may assume `n` fits in 32-bit signed integer input, but intermediate permutations may exceed 32-bit; define how you handle overflow (e.g., use 64-bit or strings).