Thread: How can I remove an integer from a random number generator?

If a randomly generated number is called once, how can I exclude it so it isn't called next time?

Please run my code:

HTML Code:

package teacher;

public class Driver {

	public static void main(String[] args) {
		
		Class x = new Class();
		x.matrix();
	}

}

HTML Code:

package teacher;

import java.util.Random;

public class Class {

	int i, j;
	boolean [][] s = new boolean[6][6];
	Random r = new Random();

	{
	s[0][0] = false; s[0][1] = true; s[0][2] = false; s[0][3] = true; s[0][4] = false; s[0][5] = false;
	s[1][0] = false; s[1][1] = true; s[1][2] = false; s[1][3] = false; s[1][4] = false; s[1][5] = true;
	s[2][0] = true; s[2][1] = false; s[2][2] = true; s[2][3] = true; s[2][4] = true; s[2][5] = true;
	s[3][0] = true; s[3][1] = false; s[3][2] = true; s[3][3] = false; s[3][4] = false; s[3][5] = true;
	s[4][0] = false; s[4][1] = true; s[4][2] = false; s[4][3] = true; s[4][4] = true; s[4][5] = true;
	s[5][0] = false; s[5][1] = true; s[5][2] = true; s[5][3] = false; s[5][4] = true; s[5][5] = false;
	}
	
	public Class(){}

	public void matrix(){
		
		for(j=0;j<6;j++){
			i = r.nextInt(6);
			while(s[i][j] = true){
				if(i == 0){
					System.out.println((j+1) + " period: Teach kindergarden.");
					//this line is supposed to remove 0 from the generator
				}
				if(i == 1){
					System.out.println((j+1) + " period: Teach " + i + "st grade.");
					//this line is supposed to remove 1 from the generator
				}
				if(i == 2){
					System.out.println((j+1) + " period: Teach " + i + "nd grade.");
					//this line is supposed to remove 2 from the generator
				}
				if(i == 3){
					System.out.println((j+1) + " period: Teach " + i + "rd grade.");
					//this line is supposed to remove 3 from the generator
				}
				if(i == 4){
					System.out.println((j+1) + " period: Teach " + i + "th grade.");
					//this line is supposed to remove 4 from the generator
				}
				if(i == 5){
					System.out.println((j+1) + " period: Teach " + i + "th grade.");
					//this line is supposed to remove 5 from the generator
				}
				else{}
				
				break;
			}
		}
	}
}

I've tried to make an arraylist and add all possible integers, but my code gives me an error:

HTML Code:

	ArrayList<Integer> x = new ArrayList<Integer>();
	x.add(0);
	x.add(1);
	x.add(2);
	x.add(3);
	x.add(4);
	x.add(5);

the errors are on the add functions, it is telling me that an '@' is expected

It worked. However, I still can't remove the random integer from the generator.

--- Update ---

Please run this code

HTML Code:

package teacher;

public class Driver {

	public static void main(String[] args) {
		
		Class x = new Class();
		x.matrix();
	}

}

HTML Code:

package teacher;

import java.util.Random;
import java.util.ArrayList;

public class Class {

	public Class(){}
	int i, j;
	boolean [][] s = new boolean[6][6];

	{
	s[0][0] = false; s[0][1] = true; s[0][2] = false; s[0][3] = true; s[0][4] = false; s[0][5] = false;
	s[1][0] = false; s[1][1] = true; s[1][2] = false; s[1][3] = false; s[1][4] = false; s[1][5] = true;
	s[2][0] = true; s[2][1] = false; s[2][2] = true; s[2][3] = true; s[2][4] = true; s[2][5] = true;
	s[3][0] = true; s[3][1] = false; s[3][2] = true; s[3][3] = false; s[3][4] = false; s[3][5] = true;
	s[4][0] = false; s[4][1] = true; s[4][2] = false; s[4][3] = true; s[4][4] = true; s[4][5] = true;
	s[5][0] = false; s[5][1] = true; s[5][2] = true; s[5][3] = false; s[5][4] = true; s[5][5] = false;
	}

	public void matrix(){
		
		ArrayList<Integer> x = new ArrayList<Integer>();

		x.add(0);
		x.add(1);
		x.add(2);
		x.add(3);
		x.add(4);
		x.add(5);
		
		Random r = new Random();
		
		for(j=0;j<5;j++){
			i = x.get(r.nextInt(6));
			while(s[i][j]){
				if(i==0){
					System.out.println((j+1) + " period: Teach kindergarden.");
					x.remove(new Integer(0));
				}
				if(i==1){
					System.out.println((j+1) + " period: Teach " + i + "st grade.");
					x.remove(new Integer(1));
				}
				if(i==2){
					System.out.println((j+1) + " period: Teach " + i + "nd grade.");
					x.remove(new Integer(2));
				}
				if(i==3){
					System.out.println((j+1) + " period: Teach " + i + "rd grade.");
					x.remove(new Integer(3));
				}
				if(i==4){
					System.out.println((j+1) + " period: Teach " + i + "th grade.");
					x.remove(new Integer(4));
				}
				if(i==5){
					System.out.println((j+1) + " period: Teach " + i + "th grade.");
					x.remove(new Integer(5));
				}
				else{
					System.out.println();
				}
				
				break;
			}
		}
	}
}

How?

--- Update ---

What does shuffling have to do with removing an int from the generator?