Hi, I wanted to know if it is possible to generate a random number between specific numbers. For example I have a board of 9 numbers (1,2,3,4,5,6,7,8,9) but the squares (2,6,8) are already occupied. Is it possible to create a random where only the remaining numbers can be output (1,3,4,5,7,9)?
Thank you.
One solution is to have a list with the available positions, "shuffle" it and take out elements.
class Test {
public static void main(String args[]) {
int[] posiciones = { 1,2,3,4,5,6,7,8,9 };
shuffleArray(posiciones);
for (int i = 0; i < posiciones.length; i++) {
System.out.print(posiciones[i] + " ");
}
}
// Algoritmo Fisher–Yates para barajar
static void shuffleArray(int[] ar) {
Random rnd = ThreadLocalRandom.current();
for (int i = ar.length - 1; i > 0; i--) {
int index = rnd.nextInt(i + 1);
int a = ar[index];
ar[index] = ar[i];
ar[i] = a;
}
}
}