Wooden Sticks(hdu1051)

Wooden Sticks

Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u

Submit Status Practice _

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

//第一行是代表测试数据t
每组数据第一行是一个整数 n ，代表木头的数量
然后 n 对数据 代表 木头的长度，和重量

需要一个机器处理这些木棒，机器开启的时候需要耗费一个单位的时间，如果第i+1个木棒的重量和长度都大于等于

第i个处理的木棒，那么将不会耗费时间，否则需要消耗一个单位的时间。

问最短时间

//贪心解决了

排个序，就行

 #include <stdio.h>
 #include <iostream>
 #include <algorithm>
 using namespace std;

 struct Node
 {
     int l,w;
 }node[],setup[];

 bool cmp(Node a,Node b)
 {
     if (a.l==b.l)
         return a.w<b.w;
     return a.l<b.l;
 }

 int main()
 {
     int t;
     cin>>t;
     while (t--)
     {
         int n;
         int i,j;
         cin>>n;
         for (i=;i<n;i++)
         {
             cin>>node[i].l>>node[i].w;
         }
         sort(node,node+n,cmp);
         int ans=;
         setup[].l=node[].l;
         setup[].w=node[].w;

         for (i=;i<n;i++)
         {
             int ok=;
             for (j=;j<ans;j++)
             {
                 if (setup[j].l<=node[i].l&&setup[j].w<=node[i].w)
                 {
                     setup[j].l=node[i].l;
                     setup[j].w=node[i].w;
                     ok=;
                     break;
                 }
             }
             if (ok==)
             {
                 setup[ans].l=node[i].l;
                 setup[ans].w=node[i].w;
                 ans++;
             }
         }
         cout<<ans<<endl;
     }
     return ;
 }