Question

想象一下，我在队列中有一个等待列表的等待列表

Service 1 - 5 minutes
Service 2 - 10 minutes
Service 3 - 5 minutes
Service 4 - 15 minutes
Service 5 - 20 minutes

如果我有两名工作人员为队列中的这五个客户提供服务，我怎么能估计下一个人在商店里走路的等待时间。

Answer 1

实际上它非常简单 - 它是"W" queue model as described by Eric Lippert。

设置一个阵列两个“工作人员”成员：

List<int>[] staff = new [] {new List<int>(), new  List<int>()};

定义你的队列：

int[] queue = new int[] {5, 10, 5, 15, 20};

然后模拟处理 - 每个后续客户将转到首先完成的服务商：

foreach (int i in queue)
{
    List<int> shortest = staff.OrderBy(s=>s.Sum()).First();
    shortest.Add(i);
}

“下一个”进入的人必须等到第一个服务商免费，这是每个服务客户的总和：

int nextTime = staff.Min(s=>s.Sum());

Console.WriteLine("The wait time for the next customer is {0} minutes",nextTime);

输出：

下一位客户的等待时间为25分钟。

Answer 2

这是一种不那么优雅的方式......

private static int GetEstimatedWaitTime(Queue<int> currentQueue, int numServers)
{
    int waitTime = 0;

    // Short-circuit if there are more servers than items in the queue
    if (currentQueue.Count < numServers) return waitTime;

    // Create a copy of the queue so we can dequeue from it
    var remainingItems = new Queue<int>();
    foreach (var item in currentQueue)
    {
        remainingItems.Enqueue(item);
    }

    // Grab an item for each server
    var itemsBeingServiced = new List<int>();
    for (int i = 0; i < numServers; i++)
    {
        itemsBeingServiced.Add(remainingItems.Dequeue());
    }

    do
    {
        // Get the shortest item left, increment our wait time, and adjust other items
        itemsBeingServiced.Sort();
        var shortestItem = itemsBeingServiced.First();
        waitTime += shortestItem;

        itemsBeingServiced.RemoveAll(item => item == shortestItem);

        for (int i = 0; i < itemsBeingServiced.Count; i++)
        {
            itemsBeingServiced[i] = itemsBeingServiced[i] - shortestItem;
        }

        // Add more items for available servers if there are any
        while (itemsBeingServiced.Count < numServers && remainingItems.Any())
        {
            itemsBeingServiced.Add(remainingItems.Dequeue());
        }

    } while (itemsBeingServiced.Count >= numServers);

    return waitTime;
}

等候名单时间计算

2 个答案: