package com.mathlearning.controller;

public class NavigationController {
  private static NavigationController instance;

  private NavigationController() {}

  public static NavigationController getInstance() {
    if (instance == null) {
      instance = new NavigationController();
    }
    return instance;
  }

  public void navigateToLogin() {
    System.out.println("导航到登录界面");
  }

  public void navigateToLevelSelection() {
    System.out.println("导航到难度选择界面");
  }

  public void navigateToQuiz() {
    System.out.println("导航到答题界面");
  }

  public void navigateToScore() {
    System.out.println("导航到分数界面");
  }
}