# POJ1065总结

## Wooden Sticks

### 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 ( 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
```

```2
1
3```

### 我的代码

``````#include<stdio.h>
#include<algorithm>

using namespace std;

struct stick
{
int w,l;
};

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

int main()
{
int t;
scanf("%d",&t);
while (t--)
{
int n;
int temp=1;
int dp;
scanf("%d",&n);
stick sticks;
for (int i=0;i<n;i++)
{
scanf("%d%d",&sticks[i].l,&sticks[i].w);
}
sort(sticks,sticks+n,cmp);
for (int i=0;i<n;i++)
{
dp[i]=1;
for (int j=0;j<i;j++)
{
if (sticks[i].l<sticks[j].l) dp[i]=dp[i]>dp[j]+1?dp[i]:dp[j]+1;
}
temp=dp[i]>temp?dp[i]:temp;
}
printf("%d\n",temp);
}
return 0;
}``````