C ++隊列模擬

Question

作為家庭作業的一部分，我應該編寫一個模擬雜貨店環境中隊列的程序。 完整的作業在鏈接頁面上進行了解釋。

我只有一個隊列時，程序正在運行，我正在嘗試根據分配說明修改它以處理多個隊列。 但是，編譯時我遇到了一些錯誤。

我知道這個問題與排隊的客戶有關; 我只是不確定如何修改程序，因此它適用於多個隊列。

非常感謝任何幫助！

錯誤消息：

qsim.cpp: In function 'int main()':
qsim.cpp:64: error: request for member 'empty' in 'line', which is of non-class type 'Queue [(((long unsigned int)(((long int)queuecount) - 1)) + 1u)]'
qsim.cpp:66: error: request for member 'dequeue' in 'line', which is of non-class type 'Queue [(((long unsigned int)(((long int)queuecount) - 1)) + 1u)]'

主要計划
主程序包括一個名為Queue的類。 我知道代碼是正確的，因為它在不同的測試程序中完美地工作。

#include <cstdlib>
#include <iostream>
#include <iomanip>
#include "queue.h"
using namespace std;

int shortest_queue(Queue q[], int queuecount)
{
    int shortest = 0;
    for (int i = 1; i < queuecount; ++i)
    {
        if(q[i].size() < q[shortest].size())
            shortest = i;
    }
    return shortest;
}

int queue_total(Queue q[], int queuecount)
{
    int custcount = 0;
    for (int i = 0; i < queuecount; ++i)
        custcount += q[i].size();
    return custcount;
}

int main()
{
    int trans_time = 0;
    int count = 0;
    int entry_time;
    int wait_sum = 0;
    int wait_time = 0;
    int seed;
    int ARV_PROB;
    int MAX_TRANS_TIME;
    int DURATION;
    int queuecount;
    int shortline;
    int temp;

    cout << "Enter these parameters of the simulation:" << endl;
    cout << " The number of queue/server pairs: ";
    cin >> queuecount;
    Queue line[queuecount];
    cout << " The probability that a customer arrives in one tick (%): ";
    cin >> ARV_PROB;
    cout << " The maximum duration of a transaction in ticks: ";
    cin >> MAX_TRANS_TIME;
    cout << " The duration of the simulation in ticks: ";
    cin >> DURATION;
    cout << "Enter a random number seed: ";
    cin >> seed;
    srand(seed);

    for (int time = 0; time < DURATION; ++time)
    {
        if ( rand() % 100 < ARV_PROB )
        {
            shortline = shortest_queue(line, queuecount);
            line[shortline].enqueue(time);
        }
        if ( trans_time == 0 )
        {
            if ( !line.empty() )
            {
                entry_time = line.dequeue();
                temp = (time - entry_time);
                if(temp > wait_time)
                    wait_time = temp;
                wait_sum += (time - entry_time);
                ++count;
                trans_time = (rand() % MAX_TRANS_TIME) + 1;
            }
        }
        else
        {
            --trans_time;
        }
        cout << setw(4) << time << setw(4) << trans_time << "  " << line << endl;
    }

    cout << count << " customers waited an average of ";
    cout << wait_sum / count << " ticks." << endl;
    cout << "The longest time a customer waited was " << wait_time << " ticks." << endl;
    cout << queue_total(line, queuecount) << " customers remain in the lines." << endl;

    return 0;
}

Answer 1

Queue line[queuecount];

if ( !line.empty() )

line不是Queue 。 它是一個Queues數組，因此您必須在要檢查的特定數組元素上調用empty() 。