POJ 1083 Moving Tables

Moving Tables
Time Limit: 1000MS   Memory Limit: 10000K
Total Submissions: 20016   Accepted: 6539

Description

The famous ACM (Advanced Computer Maker) Company has rented a floor of a building whose shape is in the following figure.

The floor has 200 rooms each on the north side and south side along the corridor. Recently the Company made a plan to reform its system. The reform includes moving a lot of tables between rooms. Because the corridor is narrow and all the tables are big, only one table can pass through the corridor. Some plan is needed to make the moving efficient. The manager figured out the following plan: Moving a table from a room to another room can be done within 10 minutes. When moving a table from room i to room j, the part of the corridor between the front of room i and the front of room j is used. So, during each 10 minutes, several moving between two rooms not sharing the same part of the corridor will be done simultaneously. To make it clear the manager illustrated the possible cases and impossible cases of simultaneous moving.

For each room, at most one table will be either moved in or moved out. Now, the manager seeks out a method to minimize the time to move all the tables. Your job is to write a program to solve the manager's problem.

Input

The input consists of T test cases. The number of test cases ) (T is given in the first line of the input file. Each test case begins with a line containing an integer N , 1 <= N <= 200, that represents the number of tables to move.
Each of the following N lines contains two positive integers s and t, representing that a table is to move from room number s to room number t each room number appears at most once in the N lines). From the 3 + N -rd
line, the remaining test cases are listed in the same manner as above.

Output

The output should contain the minimum time in minutes to complete the moving, one per line.

Sample Input

3 
4 
10 20 
30 40 
50 60 
70 80 
2 
1 3 
2 200 
3 
10 100 
20 80 
30 50 

Sample Output

10
20
30

Source

 
 
说下我的思路吧。判断区间的交集问题。看起来比较水。我开了一个数组用于计算区间被计算几次。
 
比如[3,5],[2,4]那么数组的内容就是{0,0,1,2,2,1},因为3和4都被计算了两次。
 
但是这道题的问题在于,实际上(2n+1)和(2n+2)用的是同一片走廊,也就是说算区间的时候,应该计算(room-1)/2被计算几次。
 
 
 1 #include <iostream>
 2 #include <cstdlib>
 3 #include <cstring>
 4 
 5 using namespace std;
 6 
 7 int arrange[205];
 8 
 9 int main(void)
10 {
11     int total;
12     cin >> total;
13     while(total--)
14     {
15         int tables,left,right,swp,max(0);
16         cin >> tables;
17         memset(arrange,0,sizeof(int)*205);
18         for(int i = 0;i != tables;++i)
19         {
20             cin >> left >> right;
21             if(left > right)
22             {
23                 swp = left;
24                 left = right;
25                 right = swp;
26             }
27             for(int j = (left-1)/2;j <= (right-1)/2;++j)
28             {
29                 arrange[j-1]++;    
30                 if(arrange[j-1] > max)
31                     max = arrange[j-1];
32             }
33         }
34         cout << max*10 << endl;
35     }
36     return 0;
37 }

 

posted @ 2012-04-24 17:18  gluowei39  阅读(167)  评论(0编辑  收藏  举报