[ ASSIGNMENT: ] Next smaller number with the same digits

Question

TASK :
Write a function that takes a positive integer and returns the next smaller positive integer containing the same digits.

Input >> Output Examples ::

nextSmaller(21) --> return 12
nextSmaller(531) --> return 513
nextSmaller(2071) --> return 2017

Return -1, when there is no smaller number that contains the same digits.
Also return -1 when the next smaller number with the same digits would require the leading digit to be zero.

nextSmaller(9) --> return -1
nextSmaller(111) --> return -1
nextSmaller(135) --> return -1
nextSmaller(1027) --> return -1 // 0721 is out since we don't write numbers with leading zeros

NOTE:
- Some tests will include very large
numbers!
- Test data only employs positive integers!

HappyCodings!:)

https://code.sololearn.com/Wx9Cg9Nq1zbu/?ref=app

thisOne is for --> VcC !!:)

Answer 1

https://code.sololearn.com/cggjg7OwB881/?ref=app

Answer 2

https://code.sololearn.com/cah1W4u1OjQI/?ref=app

Answer 3

Python solution without permutations, commented:

https://code.sololearn.com/ctxAG42cGmNU/#py

Answer 4

https://code.sololearn.com/cR2gOPeHCOua/?ref=app

Answer 5

what's about playing with slices? it's reduce so much permutations

https://code.sololearn.com/cOIs1rs25rBH/?ref=app

Edit: I didn't notice the other assignment about next bigger, so I did another code to get both
https://code.sololearn.com/c2WryQgXPPV4/?ref=app

Answer 6

https://code.sololearn.com/wLX5190Zs0bz/?ref=app
https://code.sololearn.com/cWhBW83yu3eF/?ref=app

Answer 7

Ruby:
Bigger & Smaller
https://code.sololearn.com/c5rG4A5xT9uG/#rb

quite new to oop en inheritance, so probably it could be optimized quite a lot

Answer 8

This is my try in Python =
https://code.sololearn.com/c8iL7gMVd2im/?ref=app

Answer 9

I used permutations of itertools in python
It works up to 10 digits, above it gives time or memory errors

https://code.sololearn.com/ccDqe40cCEs4/#py

Answer 10

my first Java code☺

https://code.sololearn.com/cNdPBhgEXjzf/?ref=app