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 1;
        else     return 0;
    }
    if(a.le<b.le)    return 1;
    else return 0;
}
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=0;
       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
",cnt);
    }
    return 0;
}