Tasks Planner

package Java_Fundamentals.MidExam;

import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class TaskPlanner {
    private static boolean isIndexValid(List<Integer> taskInt, int index) {
        return 0 <= index && index < taskInt.size();
    }

    private static void counterComplete(List<Integer> tasks) {
        int countComplete = 0;
        for (Integer t : tasks) {
            if (t == 0) {
                countComplete++;
            }
        }
        System.out.println(countComplete);
    }

    private static void counterDrop(List<Integer> tasks) {
        int countDrop = 0;
        for (Integer t : tasks) {
            if (t == -1) {
                countDrop++;
            }
        }
        System.out.println(countDrop);
    }

    private static void counterIncomplete(List<Integer> tasks) {
        int countIncomplete = 0;
        for (Integer t : tasks) {
            if (t > 0) {
                countIncomplete++;
            }
        }
        System.out.println(countIncomplete);
    }

    private static void printIncomplete(List<Integer> tasks) {
        for (int i = 0; i < tasks.size(); i++) {
            int element = tasks.get(i);
            if (element > 0 && tasks.indexOf(element) < tasks.size() - 1) {
                System.out.printf("%d ", element);
            } else if (element > 0) {
                System.out.print(element);
            }
        }
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        List<Integer> tasks = Arrays.stream(sc.nextLine().split(" ")).map(Integer::parseInt)
                .collect(Collectors.toList());

        String command = sc.nextLine();
        while (!command.equals("End")) {
            String[] commands = command.split(" +");
            String action = commands[0];
            switch (action) {
                case "Complete": {
                    int index = Integer.parseInt(commands[1]);
                    if (isIndexValid(tasks, index)) {
                        tasks.set(index, 0);
                    }
                    break;
                }
                case "Change": {
                    int index = Integer.parseInt(commands[1]);
                    int time = Integer.parseInt(commands[2]);
                    if (isIndexValid(tasks, index)) {
                        tasks.set(index, time);
                    }
                    break;
                }
                case "Drop": {
                    int index = Integer.parseInt(commands[1]);
                    if (isIndexValid(tasks, index)) {
                        tasks.set(index, -1);
                    }
                    break;
                }
                case "Count": {
                    String comm = commands[1];
                    switch (comm) {
                        case "Completed":
                            counterComplete(tasks);
                            break;
                        case "Incomplete":
                            counterIncomplete(tasks);
                            break;
                        case "Dropped":
                            counterDrop(tasks);
                            break;
                        default:
                            break;
                    }
                    break;
                }
                default:
                    break;
            }
            command = sc.nextLine();
        }
        printIncomplete(tasks);
    }
}