/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.stream.*;
import java.util.function.Function;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Random r = new Random();
        List<Integer> list = new ArrayList<>();
        int[] classes = {1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5, 5};
        for (int i = 0; i < 1000; i++) {
            list.add(classes[r.nextInt(classes.length)]);
        }
 
        Map<Integer, Long> distribution =
            list.stream().collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
        System.out.println("distribution = " + distribution);
	}
}

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