问题给出n个木头， 每个木有有li ， wi的属性， 如果后一根木头的li>=li-1 且wi>=w-1 那么不需要等加工时间，
否则加1.
第一根木头总要1个时间的加工时间，问最少需要多少时间
首先根据木头的某一个属性排序， 然后求 最长下降子序列（ 等于求出最长不下降的 个数）
题目：
Wooden Sticks
| Time Limit: 1000MS |
|
Memory Limit: 10000K |
| Total Submissions: 17044 |
|
Accepted: 7121 |
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
Sample Output
2
1
3
Source
代码：
1 #include <iostream>
2 #include <cstring>
3 #include <algorithm>
4 using namespace std;
5
6 int n;
7
8 struct W
9 {
10 int l, w;
11 bool operator < (const W &x )const
12 {
13 if( w< x.w)
14 return true;
15 else if ( w == x.w && l < x.l)
16 return true;
17
18
19 return false;
20 }
21 };
22
23 W w[5000+10];
24 int dp[10000+10];
25 void init()
26 {
27 cin>>n;
28
29 for(int i=0;i<=n;i++)
30 {
31 dp[i] = 0;
32 }
33 for(int i=0;i<n;i++)
34 {
35 cin>>w[i].l>>w[i].w;
36 }
37 sort(w,w+n);
38 }
39 int main()
40 {
41
42 int tst;
43 cin>>tst;
44 while(tst--)
45 {
46 init();
47 int cnt = 0;
48 for(int i=0;i<n;i++)
49 {
50 dp[i] =1;
51 for(int j=0;j<i;j++)
52 {
53 if( w[j].l>w[i].l)
54 {
55 dp[i] = max(dp[i],dp[j]+1);
56 }
57 cnt = max( cnt, dp[i]);
58 }
59
60 }
61 cout<<cnt<<endl;
62 }
63
64
65 return 0;
66 }
poj 1065 Wooden Sticks (dp)
原文：http://www.cnblogs.com/doubleshik/p/3538491.html
