This is a fairly simple thing to do, with a large variety of ways of completing it. A very simple solution I thought of would use 2 std::string classes if you are able to use them.
example (incomplete of course ):
You could do the same kind of thing with cstring style if you are not allowed to use std::string at this point in your class.
1) Type a random integer
2) Parse and produce the remaining values from 0-9
//This is a quick rough solution
std::string numbers = "0123456789";
std::cout << "Input a Number: ";
for ( int x = 0; x != input.length(); ++x )
for ( int y = 0; y != numbers.length(); ++y )
//Use this to possibly flag the numbers string to manipulate output below
/* if block with subscript assignment would be a good choice */
std::cout << "Leftover Output: ";
for ( int x = 0; x != numbers.length(); ++x )
//Think of how to use this in conjunction with the above loop to display the output
/* if block with subscript output would be a good choice */
std::cout << "\n";
of course there is not any range checking, or checking for incorrect input.