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).
(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
题目
一堆n根木棍。每个棒的长度和重量是预先已知的。这些木棒将由木工机械一一加工。机器需要准备一些时间(称为准备时间)来准备处理木棍。设置时间与清洁操作以及更换机器中的工具和形状有关。木工机械的准备时间如下:
(a)第一个木棍的准备时间为1分钟。
(b)在处理长度为l和重量为w的棒之后,如果l <= l'并且w <= w',则机器将不需要设置长度为l'和重量为w'的棒的设置时间。否则,将需要1分钟进行设置。
您将找到处理给定的n根木棍的最短准备时间。例如,如果您有五根长度和重量对分别为(9,4),(2,5),(1、2),(5、3)和(4,1)的摇杆,则最小设置时间应该是2分钟,因为有对(4,1),(5,3),(9,4),(1,2),(2,5)对的序列。
(b)在处理长度为l和重量为w的棒之后,如果l <= l'并且w <= w',则机器将不需要设置长度为l'和重量为w'的棒的设置时间。否则,将需要1分钟进行设置。
您将找到处理给定的n根木棍的最短准备时间。例如,如果您有五根长度和重量对分别为(9,4),(2,5),(1、2),(5、3)和(4,1)的摇杆,则最小设置时间应该是2分钟,因为有对(4,1),(5,3),(9,4),(1,2),(2,5)对的序列。
输入值
输入包含T个测试用例。在输入文件的第一行中给出了测试用例的数量(T)。每个测试用例由两行组成:第一行具有整数n,1 <= n <= 5000,代表测试例中木棍的数量,第二行包含2n个正整数l1,w1,l2, w2,...,ln,wn,每个大小最大为10000,其中li和wi分别是第i个木棍的长度和重量。2n个整数由一个或多个空格分隔。
输出量
输出应包含以分钟为单位的最短建立时间,每行一条。
样本输入
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
样本输出
2
1
3
作者描述
其实这道题和友好城市(https://www.luogu.com.cn/problem/P2782)有类似的地方
我们只需要借助结构体......就可以了
这道题没什么好说的,直接上代码
#include<cstdio> #include<iostream> #include<cstring> #include<algorithm> using namespace std; const int N=5010; struct Node{ int l,w; }e[N]; int n,T; int f[N]; bool cmp(Node A,Node B){ if(A.l==B.l)return A.w<B.w; else return A.l<B.l; } int main(){ scanf("%d",&T); while(T--){ memset(f,0,sizeof(f)); memset(e,0,sizeof(e)); scanf("%d",&n); for(int i=1;i<=n;i++){ scanf("%d%d",&e[i].l,&e[i].w); } sort(e+1,e+1+n,cmp);int ans=1; for(int i=1;i<=n;i++){ f[i]=1; for(int j=1;j<i;j++){ if(e[i].w<e[j].w&&f[i]<f[j]+1){ f[i]=f[j]+1; ans=max(ans,f[i]); } } } printf("%d ",ans); } return 0; }