make different numbers with the same digits

I have to ask the user for a positive integer ( input=('give a positive integer') and then ask him through a menu if he wants to make a bigger or smaller number with the same digits so Matlab will calculates the requested number.

[Ameer Hamza]

What if use input 999? Also, if you just want a bigger number, you can add 1.

[Jens Petit-jean]

yeah I know I think 999 just keeps the samen. No I can't just add 1 I need to make the number bigger or smaller just by changing the position of the digits.

Answer 1

[Vladimir Sovkov]

x=1342;
y=str2num(sort(num2str(x),'ascend')); % smaller
z=str2num(sort(num2str(x),'descend')); % bigger

[Jens Petit-jean]

thank you!

Answer 2

[KSSV]

str = '215' ;
num = str2num(perms(str)) ; 
greater = num(num>str2num(str)) 
lesser = num(num<str2num(str)) 

[Jens Petit-jean]

thank you!