练习1-i

题目：Problem I

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 ( 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

题意：

       之前的原题。

思路：

        虽然是原题，之前做过，但是贴代码是居然不能通过，很是郁闷，之后从网上找了几组数据测试了一下，终于把错误找出来了！！原来是在写排序函数时少写了个条件，当木头的长度相同时还需要对其重量进行排序！！

感想：

       拖延症害死人；

代码：

# include <iostream># include <vector># include <algorithm># include <fstream>using namespace std;struct wooden{    int l;    int w;    int nu;    bool operator < (const wooden &a) const    {        if(l ==  a.l)            return w <= a.w;        return l <= a.l;    }};int main(){    //ifstream cin ("b.txt");    vector<wooden> wo;    wooden wwo;    int n;    cin >> n;    while(n--)    {        wo.clear();        int m;        cin >> m;        while (m--)        {            cin >> wwo.l >> wwo.w;            wwo.nu = 1;            wo.push_back(wwo);        }        sort (wo.begin(), wo.end());        //for (int i = 0; i < wo.size(); i++)           // cout << wo[i].l <<" " << wo[i].w<<endl;        int time = 0;        for (int i = 0; i < wo.size(); i++)        {            if (wo[i].nu == 0)                continue;            time ++;            int count = i;            for (int j = 0; j < wo.size(); j++)            {                if (wo[count].w <= wo[j].w && wo[j].nu != 0)                {                    wo[j].nu = 0;                    count = j;                }            }        }        cout << time <<endl;    }    return 0;}