UVa540.Team Queue

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題目連結：http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=481

13916935

540

Team Queue

Accepted

C++

0.339

2014-07-21 06:07:37

 

Team Queue

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 thequeue from head to tail to check if some of its teammates (elements of the same team) are alreadyin the queue. If yes, it enters the queue right behind them. If not, it enters the queue at the tail andbecomes the new last element (bad luck). Dequeuing is done like in normal queues: elements areprocessed 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.

 

Input 

The input file will contain one or more test cases. Each test case begins with the number of teams t(). Then t team descriptions follow, each one consisting of the number of elementsbelonging 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 theimplementation of the team queue should be efficient: both enqueing and dequeuing of an elementshould only take constant time.

 

Output 

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 ablank line after each test case, even after the last one.

 

Sample Input 

 

23 101 102 1033 201 202 203ENQUEUE 101ENQUEUE 201ENQUEUE 102ENQUEUE 202ENQUEUE 103ENQUEUE 203DEQUEUEDEQUEUEDEQUEUEDEQUEUEDEQUEUEDEQUEUESTOP25 259001 259002 259003 259004 2590056 260001 260002 260003 260004 260005 260006ENQUEUE 259001ENQUEUE 260001ENQUEUE 259002ENQUEUE 259003ENQUEUE 259004ENQUEUE 259005DEQUEUEDEQUEUEENQUEUE 260002ENQUEUE 260003DEQUEUEDEQUEUEDEQUEUEDEQUEUESTOP0

 

Sample Output 

 

Scenario #1101102103201202203Scenario #2259001259002259003259004259005260001

解題思路：利用map的特性來儲存每個人的隊伍編號，利用queue的特性來類比題意鎖描述的操作方式。code是從粉書上讀懂之後，半寫半對拍下來的，以後仍需努力。

 

 1 #include <iostream> 2 #include <cstring> 3 #include <cctype> 4 #include <cstdio> 5 #include <cstdlib> 6 #include <algorithm> 7 #include <map> 8 #include <queue> 9 #include <numeric>10 using namespace std;11 12 const int maxt = 1e3 + 10;13 14 int main () {15     int t, kase = 0;16     int cnt = 0;17     while (cin >> t && t) {18         //cout << "***" << endl;19         printf("Scenario #%d\n", ++cnt);20         //記錄所有人的團隊編號21         map<int, int> team;22         for (int i = 0; i < t; ++ i) {23             int n, x;24             cin >> n;25             while (n --) {26                 cin >> x; team[x] = i;27             }28         }29 30         queue<int> q, q2[maxt];31         for (; ;) {32             int x;33             string cmd;34             cin >> cmd;35             if (cmd[0] == ‘S‘) {36                 break;37             } else if (cmd[0] == ‘D‘) {38                 int t = q.front();39                 cout << q2[t].front() << endl;40                 q2[t].pop();41                 if (q2[t].empty()) q.pop();  //團體t全體出隊列42             } else if (cmd[0] == ‘E‘) {43                 cin >> x;44                 int t = team[x];45                 if (q2[t].empty()) q.push(t); //團體t進入隊列46                 q2[t].push(x);47             }48         }49         cout << endl;50     }51     return 0;52 }