问题
For my computer science class we're supposed to redo a lottery code we have already created, but now using methods and arrays. This is what I've done so far, but I can't figure out for the life of me why it is still duplicating the numbers and I can't find anything online that is close enough to what we're supposed to be doing/topics we have gone over. I am very new to this.
public static void generaterand (int [] r)
{
Random randomgen = new Random();
boolean done;
int i = 0;
int j = 0;
done = false;
while (done == false)
{
for (i=0; i<6; i++)
{
r[i] = randomgen.nextInt(54)+1;
for (j=0; j<6; j++)
{
if (r[i] != r[j])
{
done = true;
}
}
}
}
System.out.printf ("Lottery Numbers: %d %d %d %d %d %d\n", r[0], r[1], r[2], r[3], r[4], r[5]);
}
回答1:
An efficient method in Java is to use a hashtree datatype, since it cannot store duplicates.
来源：https://stackoverflow.com/questions/53623086/java-random-numbers-with-no-duplicates-for-a-lottery-using-methods-and-arrays