Java实现

import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        Printer p = new Printer();
        new Thread(() -> {
            p.printA();
        }).start();
        new Thread(() -> {
            p.printN();
        }).start();
    }
}

class Printer {
    public synchronized void printN() {
        int i = 1;
        while (i <= 52) {
            System.out.print(i);
            i++;
            System.out.print(i);
            i++;
            notify();
            try {
                wait();
            } catch (Exception e) {
            }
        }
    }

    public synchronized void printA() {
        char i = 'A';
        while (i <= 'Z') {
            System.out.print(i);
            i++;
            notify();
            try {
                wait();
            } catch (Exception e) {

            }
        }
    }
}

C#

using System;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Printer p = new Printer();
            Task.Factory.StartNew(() => { p.PrintA(); });
            Task.Factory.StartNew(() => { p.PrintN(); });
            Console.ReadLine();
        }
    }
    class Printer
    {
        public object obj = new object();
        public void PrintN()
        {
            int i = 1;
            Monitor.Enter(obj);
            while (i <= 52)
            {
                Console.Write(i);
                i++;
                Console.Write(i);
                i++;
                Monitor.Pulse(obj);
                Monitor.Wait(obj);
            }
            Monitor.Exit(obj);
        }

        public void PrintA()
        {
            char a = 'A';
            Monitor.Enter(obj);
            while (a <= 'Z')
            {
                Console.Write(a);
                a++;
                Monitor.Pulse(obj);
                Monitor.Wait(obj);
            }
            Monitor.Exit(obj);
        }
    }
}