C#

int num = random.Next();

create empty list of ints called used.
N = number of random integers you want.
i = 1
  R: generate random number r
  if r is in used
    goto R
  add r to used
  i++
  if r < N
    goto R
loop ends here

Russell Jones wrote:

implemented Icomparable and randomly returned -1 or +1 and then used it for a sort?

Russell Jones wrote:

i'd create an arraylist with all the numbers in order and an empty arraylist.

then get a random number minimum 0 and less than the length of the arraylist. move that item from the first list to the second and repeat until the first arraylist is empty.

int range = 100, cnt = 10;
int[] num = new int[cnt];
Random rnd = new Random();
for (int current = 1; cnt > 0; current++) if (rnd.Next(range--) < cnt) num[num.Length - (cnt--)] = current;

do { set.Add(rand.Next(min, max)); } while (set.Count < 10);