HDUOJ------------1051Wooden Sticks

Wooden Sticks

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 9937    Accepted Submission(s): 4081

Problem Description

There is a pile of n wooden sticks. The length and weight of each stick are known in advance. The sticks are to be processed by a woodworking machine in one by one fashion. It needs some time, called setup time, for the machine to prepare processing a stick. The setup times are associated with cleaning operations and changing tools and shapes in the machine. The setup times of the woodworking machine are given as follows:

(a) The setup time for the first wooden stick is 1 minute.
(b) Right after processing a stick of length l and weight w , the machine will need no setup time for a stick of length l' and weight w' if l<=l' and w<=w'. Otherwise, it will need 1 minute for setup.

You are to find the minimum setup time to process a given pile of n wooden sticks. For example, if you have five sticks whose pairs of length and weight are (4,9), (5,2), (2,1), (3,5), and (1,4), then the minimum setup time should be 2 minutes since there is a sequence of pairs (1,4), (3,5), (4,9), (2,1), (5,2).

 

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 consists of two lines: The first line has an integer n , 1<=n<=5000, that represents the number of wooden sticks in the test case, and the second line contains n 2 positive integers l1, w1, l2, w2, ..., ln, wn, each of magnitude at most 10000 , where li and wi are the length and weight of the i th wooden stick, respectively. The 2n integers are delimited by one or more spaces.

 

Output

The output should contain the minimum setup time in minutes, one per line.

 

Sample Input

3

5

4 9 5 2 2 1 3 5 1 4

3

2 2 1 1 2 2

3

1 3 2 2 3 1

 

Sample Output

2 1 3

 

Source

Asia 2001, Taejon (South Korea)

采用的是，常规的方法。。。。

先进行排序，人选一个作为第一优先级...

比如以第一个聚类...以重量作为依据排序..

2 1

5 2

1 4

3 5

4 9

序列排好了...然后那样每次拿掉一条递增的序列，并统计即可！

代码：

 #include<cstdio>
 #include<vector>
 #include<algorithm>
 #include<iostream>
 using namespace std;
 typedef struct
 {
     int we;
     int le;
     int tag;
 }go;
 int cmp(go const  a, go const b)
 {
     /*升序*/
     if(a.le==b.le)
     {
         if(a.we<b.we)    return ;
         else     return ;
     }
     if(a.le<b.le)    return ;
     else return ;
 }
 int main()
 {
     int t,n,cnt;
     vector<go>st;
     go tem;
     scanf("%d",&t);
     while(t--)
     {
         st.clear();
         scanf("%d",&n);
         while(n--)
         {
             scanf("%d%d",&tem.le,&tem.we);
             tem.tag=true;
             st.push_back(tem);
         }
        sort(st.begin(),st.end(),cmp);
        vector<go>::iterator it,tem;
        cnt=;
        bool falg;
        while(!st.empty())
        {
            falg=true;
        for(it=st.begin(); it!=st.end();it++)
          {
            if(it->tag&&falg) tem=it;
           if(it->tag&&tem->we<=it->we)
            {
                tem=it;
                it->tag=false;
                falg=false;
            }
          }
          if(!falg) cnt++;
          else break;
        }
        printf("%d\n",cnt);
     }
     return ;
 }