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贪心 --- 巧妙解法Moving Tables

Time

Limit: 2000/1000 MS (Java/Others)    Memory Limit:

65536/32768 K (Java/Others)

Total Submission(s):

18319    Accepted Submission(s):

6268

Problem Description

The famous ACM (Advanced Computer Maker) Company has

rented a floor of a building whose shape is in the following figure.

贪心 --- 巧妙解法Moving Tables

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.

贪心 --- 巧妙解法Moving Tables

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. 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

N+3-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

【题目来源】

题目意思很容易理解,这里就不过多说了。

【题目分析】

贪心算法,我看很多人用区间标记的方法写了一百多行,其实根本不用,直接就统计排序就行,不仅好理解,而且代码也很精简。