1014 Waiting in Line

Suppose a bank has N windows open for service. There is a yellow line in front of the windows which devides the waiting area into two parts. The rules for the customers to wait in line are:

• The space inside the yellow line in front of each window is enough to
  contain a line with $M$ customers. Hence when all the $N$ lines are full,
  all the customers after (and including) the $(NM+1)$st one will have to
  wait in a line behind the yellow line.

• Each customer will choose the shortest line to wait in when crossing the yellow line. If there are two or more lines with the same length, the customer will always choose the window with the smallest number.

• $Custome{r}_i$​​ will take $T_i$​​ minutes to have his/her transaction processed.

• The first $N$ customers are assumed to be served at 8:00am.

Now given the processing time of each customer, you are supposed to tell the exact time at which a customer has his/her business done.

For example, suppose that a bank has 2 windows and each window may have 2 custmers waiting inside the yellow line. There are 5 customers waiting with transactions taking 1, 2, 6, 4 and 3 minutes, respectively. At 08:00 in the morning, customer​1​​ is served at window​1​​ while customer​2​​ is served at window​2​​. Customer​3​​ will wait in front of window​1​​ and customer​4​​ will wait in front of window​2​​. Customer​5​​ will wait behind the yellow line.

At 08:01, customer​1​​ is done and customer​5​​ enters the line in front of window​1​​ since that line seems shorter now. Customer​2​​ will leave at 08:02, customer​4​​ at 08:06, customer​3​​ at 08:07, and finally customer​5​​ at 08:10.
Input Specification:

Each input file contains one test case. Each case starts with a line containing 4 positive integers: $N(\le 20$, number of windows), $M(\le 10$, the maximum capacity of each line inside the yellow line), $K(\le 1000$, number of customers), and $Q(\le 1000$, number of customer queries).

The next line contains $K$ positive integers, which are the processing time of the $K$ customers.

The last line contains Q positive integers, which represent the customers who are asking about the time they can have their transactions done. The customers are numbered from 1 to K.

Output Specification:

For each of the Q customers, print in one line the time at which his/her transaction is finished, in the format HH:MM where HH is in [08, 17] and MM is in $[00,59]$. Note that since the bank is closed everyday after 17:00, for those customers who cannot be served before 17:00, you must output Sorry instead.
Sample Input:

2 2 7 5
1 2 6 4 3 534 2
3 4 5 6 7

Sample Output:

08:07
08:06
08:10
17:00
Sorry

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题解：

模拟题，可以使用一个队列数组来模拟窗口队伍，需要注意的是：如果服务在17:00之前开始，即使超时，仍然是允许的，而不是输出Sorry，以及对于这类场景模拟题，一般是不会太卡时间，所以只需按照题目描述一步一步的实现，最后再进行剪枝即可；
说明一下，对于< queue >中元素的修改，并不会影响到元素本身的值；

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#include <iostream>
#include <queue>
#include <iomanip>
using namespace std;
#define MAXLINE 20
#define MAXTIME 0x3FFFFFFF

struct Customer{
    int id, processing;
    int time = MAXTIME;		// 完成时间
};
int N,M,K,Q;
queue<Customer> q[20];

int FindShortest(){		// 寻找最短队列
    int MinQ = MAXLINE, line = 0;
    for(int i=0;i<N;i++){
        if(q[i].size() < MinQ){
            MinQ = q[i].size();
            line = i;
        }
    }
    return line;
}

int FindQuickest(){		// 寻找下一个最快完成的队列
    int MinT = MAXTIME, line = 0;
    for(int i=0;i<N;i++){
        if(q[i].front().processing < MinT && !q[i].empty()){
            MinT = q[i].front().processing;
            line = i;
        }
    }
    return line;
}

int main()
{
    int time = 0;
    Customer C[1005];
    cin>>N>>M>>K>>Q;
    for(int i=1;i<=K;i++){
        C[i].id = i;
        cin>>C[i].processing;
    }

    int cont_in = 0, index = 1;
    int id, processing, line;
    do{
        while(cont_in < N*M && index <= K ){
            q[FindShortest()].push(C[index++]);
            cont_in++;
        }

        line = FindQuickest();
        id = q[line].front().id;
        processing = q[line].front().processing;
        for(int i=0;i<N;i++){
            if(!q[i].empty())
                q[i].front().processing -= processing;
        }
        q[line].pop();
        time += processing;
        C[id].time = time;
        cont_in--;
    }while(cont_in > 0);

    int hour,minute;
    for(int i=0;i<Q;i++){
        cin>>id;
        if(C[id].time - C[id].processing < 540){
            hour = C[id].time/60;
            minute = C[id].time%60;
            cout<<setw(2)<<setfill('0')<<hour+8;
            cout<<":";
            cout<<setw(2)<<setfill('0')<<minute<<endl;
        }
        else
            cout<<"Sorry\n";          // 如果服务在17:00之前开始，即使超时，仍然是允许的，而不是输出Sorry
    }
}