1 编写单进程多线程程序，实现一个线程A将另外一个线程B的从标准输入的字符串反序输出。

2 编写单进程多线程程序，用信号量实现一个线程A随机生成一个0-100的整数，另外一个线程B将此数平方后打印输出，要求每秒钟显示一次。

3 编写单进程多线程程序，用互斥锁实现一个线程A随机生成一个0-100的整数，另外一个线程B将此数平方后打印输出，要求每秒钟显示一次。-A single process writing multi-threaded program, implement a thread A thread B will be another string from standard input output in reverse order. 2 single-process multi-threaded programs written using semaphore to implement a thread A generates a random integer 0-100, another thread B after this number of square printed output, requires a second display. 3 single-process multi-threaded programs written using a thread mutex to achieve a 0-100 A randomly generated integer, another thread B after this number of square printed output, requires a second display.