请通过继承的方法创建一个多线程程序，并用 Runnable 接口创建一个多线程程序，最后建立两个线程 a 和 b , a 线程每隔0.1s输出一个' a '，共输出10个' a : b 线程每隔0.2s输出一个 b ，共输出10个。

使用继承方式创建多线程程序：

public class MyThread extends Thread {
    private String name;
    private int count;

    public MyThread(String name, int count) {
        this.name = name;
        this.count = count;
    }

    @Override
    public void run() {
        for (int i = 0; i < count; i++) {
            System.out.print(name + " ");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

使用 Runnable 接口创建多线程程序：

public class MyRunnable implements Runnable {
    private String name;
    private int count;

    public MyRunnable(String name, int count) {
        this.name = name;
        this.count = count;
    }

    @Override
    public void run() {
        for (int i = 0; i < count; i++) {
            System.out.print(name + " ");
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

主函数中启动两个线程：

public static void main(String[] args) {
    Thread a = new MyThread("a", 10);
    Thread b = new Thread(new MyRunnable("b", 10));
    a.start();
    b.start();
}