01. Sort Numbers

import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int firstNum = Integer.parseInt(scanner.nextLine()),
            secondNum = Integer.parseInt(scanner.nextLine()),
            thirdNum = Integer.parseInt(scanner.nextLine());

        for (int i = 0; i < 3; i++) {
            if (firstNum > secondNum && firstNum > thirdNum) {
                System.out.println(firstNum);
                firstNum = Integer.MIN_VALUE;
            } else if (secondNum > firstNum && secondNum > thirdNum) {
                System.out.println(secondNum);
                secondNum = Integer.MIN_VALUE;
            } else {
                System.out.println(thirdNum);
                thirdNum = Integer.MIN_VALUE;
            }
        }
    }
}

Решение с масив:

import java.util.Scanner;
import java.util.Arrays;

class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int[] numbers = new int[3];

        for (int i = 0; i < 3; i++) {
            numbers[i] = Integer.parseInt(scanner.nextLine());
        }

        Arrays.sort(numbers);

        for (int i = 2; i >= 0; i--) {
            System.out.println(numbers[i]);
        }
    }
}