Team Queue UVA - 540
阅读原文时间:2023年07月08日阅读:2

  Queues and Priority Queues are data structures which are known to most computer scientists. The Team Queue, however, is not so well known, though it occurs often in everyday life. At lunch time the queue in front of the Mensa is a team queue, for example.

  In a team queue each element belongs to a team. If an element enters the queue, it first searches the queue from head to tail to check if some of its teammates (elements of the same team) are already in the queue. If yes, it enters the queue right behind them. If not, it enters the queue at the tail and becomes the new last element (bad luck). Dequeuing is done like in normal queues: elements are processed from head to tail in the order they appear in the team queue.

  Your task is to write a program that simulates such a team queue.

  The input file will contain one or more test cases. Each test case begins with the number of teams t (1 ≤ t ≤ 1000). Then t team descriptions follow, each one consisting of the number of elements belonging to the team and the elements themselves. Elements are integers in the range 0..999999. A team may consist of up to 1000 elements.

  Finally, a list of commands follows. There are three different kinds of commands:

  • ENQUEUE x — enter element x into the team queue

  • DEQUEUE — process the first element and remove it from the queue

  • STOP — end of test case

      The input will be terminated by a value of 0 for t.

      Warning: A test case may contain up to 200000 (two hundred thousand) commands, so the implementation of the team queue should be efficient: both enqueing and dequeuing of an element should only take constant time.

      For each test case, first print a line saying ‘Scenario #k’, where k is the number of the test case. Then, for each ‘DEQUEUE’ command, print the element which is dequeued on a single line. Print a blank line after each test case, even after the last one.

    2
    3 101 102 103
    3 201 202 203
    ENQUEUE 101
    ENQUEUE 201
    ENQUEUE 102
    ENQUEUE 202
    ENQUEUE 103
    ENQUEUE 203
    DEQUEUE
    DEQUEUE
    DEQUEUE
    DEQUEUE
    DEQUEUE
    DEQUEUE
    STOP
    2
    5 259001 259002 259003 259004 259005
    6 260001 260002 260003 260004 260005 260006
    ENQUEUE 259001
    ENQUEUE 260001
    ENQUEUE 259002
    ENQUEUE 259003
    ENQUEUE 259004
    ENQUEUE 259005
    DEQUEUE
    DEQUEUE
    ENQUEUE 260002
    ENQUEUE 260003
    DEQUEUE
    DEQUEUE
    DEQUEUE
    DEQUEUE
    STOP
    0

    Scenario #1
    101
    102
    103
    201
    202
    203

    Scenario #2
    259001
    259002
    259003
    259004
    259005
    260001

这个题目不用紫皮书上的方法好像没有啥简单点的方法了。用的双队列,因为题目的意思是每一个排队成员都有属于自己的队伍,因此没进来一个人都会去找到自己的团队里面的最后一个的后面排队。因此用队列数组存储每一个小团队的队列,然后再加一个队列来存储各个团队的队列。更具体的壳代码和紫皮书就好。

#include<algorithm>
#include <iostream>
#include<sstream>
#include<map>
#include<string>
#include<vector>
#include<set>
#include<stack>
#include<queue>

using namespace std;

int main()
{
    int m,id, n,num=1;
    while (1){
        map<int, int>teams;         //记录组名;
        cin >> m;
        if (!m)break;
        for (int i = 0;i < m;i++){
            cin >> n;
            for (int j = 0;j < n;j++){
                cin >> id;
                teams[id] = i;
            }
        }
        queue<int>q1, q2[1010];
        string s;
        cout << "Scenario #" << num++ << endl;
        while (cin >> s && s != "STOP")
        {
            if (s == "DEQUEUE"){
                cout << q2[q1.front()].front() << endl;
                q2[q1.front()].pop();
                if (q2[q1.front()].empty())q1.pop();
            }
            else {
                cin >> id;
                if (q2[teams[id]].empty())q1.push(teams[id]);
                q2[teams[id]].push(id);
            }
        }
        cout << endl;
    }
}