贪心-Wooden Sticks

先将火柴按照长度（或重量）优先排序，在不断遍历数组，找出其中重量（长度）递增子序列，并标记

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).

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

#include<iostream>

#include<algorithm>

using namespace std;

struct wood{

    int l;

    int w;

    int flag;

}W[];

bool cmp(wood w1, wood w2){

    if(w1.l<w2.l )

    return true;

    else if(w1.l==w2.l && w1.w<=w2.w)

    return true;

    return false;

}

int main()

{

    int t,n;

    cin>>t;

    while(t--){

        cin>>n;

        for(int i=;i<n;i++){

            cin>>W[i].l>>W[i].w;

            W[i].flag=;

        }

        sort(W,W+n,cmp);

        //for(int i=0;i<n;i++)

        //cout<<W[i].l<<" "<<W[i].w<<endl;

        int tw;

        int result=;

        for(int i=;i<n;i++){

            if(W[i].flag)

            continue;

            tw=W[i].w;

            W[i].flag=;

            for(int j=;j<n;j++){

                if(W[j].flag)

                continue;

                if(W[j].w>=tw){

                    tw=W[j].w;

                    W[j].flag=;

                }

            }

            result++;

        }

        cout<<result<<endl;

    }

    return ;

}

巴特西

贪心-Wooden Sticks

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