Sorting digits of an integer

Question

You are given an integer 51234 (say) we need to sort the digits of a number the output will be 12345.

How to do it without using array ?

Answer 1

Sure arrays are out, but we've got a better container anyway:

void foo(unsigned i) {
  std::set digits;
  do {
    digits.insert(`0` + i % 10);
    i /= 10;
  while(i!=0);
}

Use multiset if your input includes numbers like 887 that should be printed as 788