URAL1052[Rabbit hunt]

水题，O(n^3)过了。

CODE:

/*

PROGRAM: $PROGRAM

AUTHOR: Su Jiao

DATE: 2010-3-27

DESCRIPTION:

$DESCRIPTION

*/

#include <iostream>

using std::cin;

using std::cout;

#include <fstream>

using std::ifstream;

using std::ofstream;

#include <sstream>

using std::stringstream;

using std::endl;

#include <vector>

using std::vector;

#include <string>

using std::string;

#include <stack>

using std::stack;

#include <queue>

using std::queue;

#include <set>

using std::set;

#include <map>

using std::map;

using std::pair;

using std::make_pair;

#include <algorithm>

using std::sort;

#include <cassert>

//using std::assert;

 

class Application

{

      int N;

      vector<pair<int,int> > rabbit;

      public:

      Application()

      {

                    cin>>N;

                    rabbit.resize(N);

                    for (int i=0;i<N;i++)

                        cin>>rabbit[i].first>>rabbit[i].second;

      }

      int run()

      {

          #define can(a,b,c) (rabbit[a].first-rabbit[b].first)\

                             *(rabbit[a].second-rabbit[c].second)\

                             ==(rabbit[a].first-rabbit[c].first)\

                             *(rabbit[a].second-rabbit[b].second)

          int K=0;

          for (int a=0;a<N;a++)

              for (int b=a+1;b<N;b++)

              {

                  int counter=2;

                  for (int c=b+1;c<N;c++)

                      if (can(a,b,c)) counter++;

                  if (counter>K) K=counter;

              }

          cout<<K<<endl;

          #undef can

          return 0;

      }

};

 

int main()

{

    Application app;

    return app.run();

}