POJ1065 Wooden Sticks

Wooden Sticks

Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 23594 Accepted: 10162

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

213

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题目的意思是加工木材，每次机器可以加工长度和质量大于等于当前的，否则要重新调整，问最少调整几次

思路：按L排序，对M进行最长上升子序列个数，开一个数组贪心维护一个单调递减的序列

#include <iostream>#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <queue>#include <stack>#include <string>#include <set>#include<vector>#include <map>using namespace std;#define inf 0x3f3f3f3fstruct node{int x,y;}p[5500];int a[10005];bool cmp(node a,node b){    if(a.x!=b.x)    return a.x<b.x;    return a.y<b.y;}int main(){    int n,T;        for(scanf("%d",&T);T--;)        {            scanf("%d",&n);            for(int i=0;i<n;i++)            scanf("%d%d",&p[i].x,&p[i].y);            sort(p,p+n,cmp);            int cnt=1;            a[1]=p[0].y;            for(int i=1;i<n;i++)            {                int flag=0;                for(int j=1;j<=cnt;j++)                {                    if(a[j]<=p[i].y)                    {                        flag=1;                        a[j]=p[i].y;                        break;                    }                }                    if(!flag)                    {                        a[++cnt]=p[i].y;                    }            }            printf("%d\n",cnt);        }        return 0;}