设计并实现一个计算线程与一个I/O线程共享缓冲区的同步与通信，程序要求:

两个线程,共享公共变量a；

线程1负责计算(1到100的累加，每次加一个数)；

线程2负责打印（输出累加的中间结果)；

主进程等待子线程退出。

-Design and implement a computation thread and an I/O thread shared buffer synchronization and communication, procedural requirements: two threads share a common variable a　Thread 1 is responsible for calculating (counting　1 to 100, each plus a number)　thread 2 responsible for printing (cumulative output of intermediate results)　the main thread waits for the child process exits.