游乐园预订

Question

该系统允许骑手在不需要等待的情况下预订一个位置。骑手只需在一个程序中输入一个名字，就可以预订一个位置。购买VIP通行证的骑手可以跳过普通骑手，直到最后一个VIP乘客排队。贵宾先上飞机。(考虑到迪士尼乐园的平均等待时间约为45分钟，这可能是一个有用的计划。)对于此系统，员工手动选择何时出动骑行(从而将下一个骑手从线路前部移除)。

riders_per_ride = 3  # Num riders per ride to dispatch

line = []  # The line of riders
num_vips = 0  # Track number of VIPs at front of line

menu = ('(1) Reserve place in line.\n'  # Add rider to line
        '(2) Reserve place in VIP line.\n'  # Add VIP
        '(3) Dispatch riders.\n'  # Dispatch next ride car
        '(4) Print riders.\n'
        '(5) Exit.\n\n')

user_input = input(menu).strip().lower()



while user_input != '5':
    if user_input == '1':  # Add rider 
        name = input('Enter name:').strip().lower()
        print(name)
        line.append(name)

    elif user_input == '2':  # Add VIP
        #print('FIXME: Add new VIP')
        # Add new rider behind last VIP in line
        name = input('Enter name:').strip().lower()
        # Hint: Insert the VIP into the line at position num_vips.
        line.insert(num_vips,name)
        #Don't forget to increment num_vips.
        num_vips += 1

    elif user_input == '3':  # Dispatch ride
        #print('FIXME: Remove riders from the front of the line.')
        # Remove last riders_per_ride from front of line.
        for i in range(riders_per_ride):
            line.pop(0)
        # Don't forget to decrease num_vips, if necessary.
        #num_vips -= 1

    elif user_input == '4':  # Print riders waiting in line
        print(f'{len(line)} person(s) waiting:'.format(len(line)), line)

    else:
        print('Unknown menu option')

    user_input = input('Enter command: ').strip().lower()
    print(user_input)

当我试图从线的前面移除骑手时，我一直在循环中得到一个错误。

Answer 1

您的分派长度总是等于3，但您的列表可能不包含3项，因此您需要检查它。下面的代码修复了这个问题：

riders_per_ride = 3  # Num riders per ride to dispatch

line = []  # The line of riders
num_vips = 0  # Track number of VIPs at front of line

menu = (
    "(1) Reserve place in line.\n"  # Add rider to line
    "(2) Reserve place in VIP line.\n"  # Add VIP
    "(3) Dispatch riders.\n"  # Dispatch next ride car
    "(4) Print riders.\n"
    "(5) Exit.\n\n"
)

user_input = input(menu).strip().lower()


while user_input != "5":
    if user_input == "1":  # Add rider
        name = input("Enter name:").strip().lower()
        print(name)
        line.append(name)

    elif user_input == "2":  # Add VIP
        # print('FIXME: Add new VIP')
        # Add new rider behind last VIP in line
        name = input("Enter name:").strip().lower()
        # Hint: Insert the VIP into the line at position num_vips.
        line.insert(num_vips, name)
        # Don't forget to increment num_vips.
        num_vips += 1

    elif user_input == "3":  # Dispatch ride
        # print('FIXME: Remove riders from the front of the line.')
        # Remove last riders_per_ride from front of line.
        for i in range(min(riders_per_ride, len(line))):
            line.pop(0)
        # Don't forget to decrease num_vips, if necessary.
        # num_vips -= 1

    elif user_input == "4":  # Print riders waiting in line
        print(f"{len(line)} person(s) waiting:".format(len(line)), line)

    else:
        print("Unknown menu option")

    user_input = input("Enter command: ").strip().lower()
    print(user_input)