Question

考虑下面的代码，它接受输入过程及其到达时间并根据FCFS算法对它们进行排序，所以我一直在考虑计算平均等待时间的算法但是所有都是假的，所以有任何建议吗？

进程=输入（“输入以逗号分隔的处理时间和到达时间：”）

    BurstTimes = Processes[::2]
    ArrivalTimes = Processes[1::2]
    print '   Burst Times:', BurstTimes, '\n', '   Arrival Times', ArrivalTimes,'\n',
    list1, list2 =  BurstTimes, ArrivalTimes
    indices1 = range(len(list1))
    indices1.sort(key=lambda x: list1[x])
    list1 = map(lambda i: list1[i], indices1)
    print 'The Processes executed in this order: ', list1 
    Wt_Time = 0

计算总时间的代码：

print'按此顺序执行的进程：'，list1

    process_queue = []
    total_wtime = 0
    for i in range(len(list2)):
        process_queue[i].append(int(list1[i])
        total_wtime += process_queue[i][1]

并在最后一行给出错误

Answer 1

process_queue [I] .append（INT（list1的[I]）

您要将list1的第i个元素追加到process_queue列表中，您应该注意list1 [i]不是列表而是整数。在下一行中，您正在尝试访问

total_wtime + = process_queue [i] [1]

process_queue [i]的第一个元素，但它不是二维数组

total_wtime + = process_queue [i]

应该有效。

Answer 2

# Author:Geraldo Braho
process_queue = []
total_wtime = 0
n = int(raw_input('Enter the total numbers of processes: '))
for i in xrange(n):
    process_queue.append([])#append a list object to the list
    process_queue[i].append(raw_input('Enter process name: '))
    process_queue[i].append(int(raw_input('Enter process arrival Time : ')))
    total_wtime += process_queue[i][1]
    process_queue[i].append(int(raw_input('Enter Process CPU bustTime : ')))
    print ''

process_queue.sort(key = lambda process_queue:process_queue[1])

print 'ProcessName\tArrivalTime\tBurstTime'
for i in xrange(n):
    print process_queue[i][0],'\t\t',process_queue[i][1],'\t\t',process_queue[i][2]

print 'Total waiting time: ',total_wtime
print 'Average waiting time: ',(total_wtime/n)

Answer 3

概念：https://www.geeksforgeeks.org/program-fcfs-scheduling-set-2-processes-different-arrival-time/

processes = [
    {"pid": "P0", "burst_time": 5, "arrival_time": 0, "service_time": None, "waiting_time": None},
    {"pid": "P1", "burst_time": 3, "arrival_time": 1, "service_time": None, "waiting_time": None},
    {"pid": "P2", "burst_time": 8, "arrival_time": 2, "service_time": None, "waiting_time": None},
    {"pid": "P3", "burst_time": 6, "arrival_time": 3, "service_time": None, "waiting_time": None}
]

# No waiting time for first process
processes[0]["waiting_time"] = 0
# Service_time of the first process is it's arrival time
processes[0]["service_time"] = processes[0]["arrival_time"]

for i in range(1, len(processes)):
    # Case where process comes when processor is in idle state
    if processes[i]["arrival_time"] > (processes[i - 1]["service_time"] + processes[i - 1]["burst_time"]):
        processes[i]["service_time"] = processes[i]["arrival_time"]
    else:
        processes[i]["service_time"] = processes[i - 1]["service_time"] + processes[i - 1]["burst_time"]

    processes[i]["waiting_time"] = processes[i]["service_time"] - processes[i]["arrival_time"]

total_waiting_time = 0

for process in processes:
    total_waiting_time += process["waiting_time"]

avg_waiting_time = total_waiting_time / len(processes)

print("Average Waiting Time:", avg_waiting_time)

算法计算python中FCFS调度的等待时间

3 个答案: