Random Number but Don't Repeat

Question

I would like to generate a random number less than 50, but once that number has been generated I would like it so that it cannot be generated again.

Thanks for the h

Answer 1

Please see: Fisher–Yates shuffle:

public static void shuffle (int[] array) 
{
    Random rng = new Random();       // i.e., java.util.Random.
    int n = array.length;            // The number of items left to shuffle (loop invariant).
    while (n > 1) 
    {
        n--;                         // n is now the last pertinent index
        int k = rng.nextInt(n + 1);  // 0 <= k <= n.
        int tmp = array[k];
        array[k] = array[n];
        array[n] = tmp;
    }
}