HDOJ 1050 Moving Tables

Problem 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. 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
   
   
   
   
   
   
   
   

    
    
    
    题解
   
   
   
   
   
   
   
   

    
    
    
    首先这道题需要进行抽象，抽象成区间覆盖数量的最大值，因为有共同区间的两次移动必定不可能放在一次中移动完成，而只要找出这个最大值便是答案，其次，这道题的这种排列方式尤其特殊性，必须加以自习分析与考察（具体怎么做，就要多考察几种最好差的比较多的答案来看），其次就是还要注意细节问题，本题中越到后来就越会认为给出的就是区间范围，而忘了有可能出现的大小问题
    
    
    
    
//
//  main.cpp
//  Moving Tables
//
//  Created by 张嘉韬 on 16/3/17.
//  Copyright © 2016年 张嘉韬. All rights reserved.
//

#include <iostream>
#include <cstring>
using namespace std;
int main(int argc, const char * argv[]) {
    //freopen("/Users/zhangjiatao/Desktop/input.txt","r",stdin);
    int T;
    cin>>T;
    for(int k=1;k<=T;k++)
    {
        int n,a[600][2],map[600],maxnum=0;
        memset(map,0,sizeof(map));
        cin>>n;
        for(int i=1;i<=n;i++)
        {
            cin>>a[i][0]>>a[i][1];// 0 is s ,i is t
            if(a[i][0]>a[i][1])
            {
                int temp=a[i][0];
                a[i][0]=a[i][1];
                a[i][1]=temp;
            }
        }
        for(int i=1;i<=n;i++)
        {
            if(a[i][0]%2==0) map[a[i][0]-1]++;
            if(a[i][1]%2!=0) map[a[i][1]]++;
            for(int j=a[i][0];j<=a[i][1]-1;j++)
            {
                map[j]++;
            }
        }
        for(int i=1;i<=399;i++)
        {
            if(map[i]>maxnum) maxnum=map[i];
        }
        cout<<maxnum*10<<endl;
    }
    return 0;
}