URAL1010[Discrete Function]

可以证明这样的两个点一定是相邻的。
如图：

明显红线没有绿线优，绿线又没有紫线优，如此一直推，会发现最后一定是两个相邻点。
CODE:

/*

PROGRAM: $PROGRAM

AUTHOR: Su Jiao

DATE: 2010-3-13

DESCRIPTION:

$DESCRIPTION

*/

#include <iostream>

using std::cin;

using std::cout;

using std::endl;

#include <sstream>

using std::stringstream;

#include <vector>

using std::vector;

#include <string>

using std::string;

#include <stack>

using std::stack;

#include <queue>

using std::queue;

#include <map>

using std::map;

using std::pair;

using std::make_pair;

#include <algorithm>

using std::sort;

#include <cassert>

//using std::assert;

 

class Application

{

      static const int oo=~(1<<31);

      int N;

      vector<double> f;

      public:

      Application()

      {

                   cin>>N;

                   f.resize(N);

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

                       cin>>f[i];

      }

      int run()

      {

          //max{abs(f[i-1]-f[i]) ,2<=i<=N}

          double max=-oo;

          int max_i;

          for (int i=1;i<N;i++)

          {

              double abs_k=f[i-1]>f[i]?f[i-1]-f[i]:f[i]-f[i-1];

              if (abs_k>max)

              {

                 max=abs_k;

                 max_i=i;

              }

          }

          cout<<max_i+1–1<<” “<<max_i+1<<endl;

          return 0;

      }

};

 

int main()

{

    Application app;

    return app.run();

}