hdu1065 Wooden Sticks

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 ( 9 , 4 ) , ( 2 , 5 ) , ( 1 , 2 ) , ( 5 , 3 ) , and ( 4 , 1 ) , then the minimum setup time should be 2 minutes since there is a sequence of pairs ( 4 , 1 ) , ( 5 , 3 ) , ( 9 , 4 ) , ( 1 , 2 ) , ( 2 , 5 ) .

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 2n 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

最小上升子序列的个数

#include <algorithm>#include <iostream>#include <cstring>using namespace std;struct node{    int length,weight;}a[5005];bool cmp(node a,node b){    if(a.length==b.length)        return a.weight<b.weight;    return a.length<b.length;}int main(){    int t,flag[5005];    cin>>t;    while(t--)    {        int n;        cin>>n;        for(int i=0;i<n;++i)            cin>>a[i].length>>a[i].weight;        sort(a,a+n,cmp);        int min=0;        node s=a[0];        memset(flag,0,sizeof(flag));        for(int i=0;i<n;++i)        {            s=a[i];          if(!flag[i])         {            for(int j=i+1;j<n;++j)            {                if(!flag[j]&&a[j].weight>=s.weight)                   {                    flag[j]=1;                       s=a[j];                   }            }            min++;         }        }        cout<<min<<endl;    }    return 0;}