这是一个关于作业调度的程序，包含了FCFS，SJF和HRN三种算法-Here is a job scheduling process, including the FCFS, SJF, and three algorithms HRN

先来先服务和短作业优先的操作系统进程调度算法，使用C++实现，测试可用-First come first serve and short operating priority operating system process scheduling algorithm using C++ implementation, testing available