先来先服务算法 python实现

先来先服务（First-Come, First-Served，FCFS）算法是一种简单的进程调度算法，按照进程到达的先后顺序进行调度。实现该算法的代码如下：

class Process:
    def __init__(self, pid, arrival_time, burst_time):
        self.pid = pid
        self.arrival_time = arrival_time
        self.burst_time = burst_time

def fcfs(processes):
    n = len(processes)
    waiting_time = [0] * n
    turnaround_time = [0] * n
    total_waiting_time = 0
    total_turnaround_time = 0
    current_time = 0
    
    for i in range(n):
        if current_time < processes[i].arrival_time:
            current_time = processes[i].arrival_time
        waiting_time[i] = current_time - processes[i].arrival_time
        turnaround_time[i] = waiting_time[i] + processes[i].burst_time
        current_time += processes[i].burst_time
        total_waiting_time += waiting_time[i]
        total_turnaround_time += turnaround_time[i]
    
    avg_waiting_time = total_waiting_time / n
    avg_turnaround_time = total_turnaround_time / n
    
    print("Process\tArrival Time\tBurst Time\tWaiting Time\tTurnaround Time")
    for i in range(n):
        print(f"{processes[i].pid}\t\t{processes[i].arrival_time}\t\t{processes[i].burst_time}\t\t{waiting_time[i]}\t\t{turnaround_time[i]}")
    print(f"Average waiting time: {avg_waiting_time:.2f}")
    print(f"Average turnaround time: {avg_turnaround_time:.2f}")

# 示例用法
processes = [Process(1, 0, 5), Process(2, 1, 3), Process(3, 2, 8)]
fcfs(processes)