#include<math.h>

 #include<stdio.h>

 #include<stdlib.h>

 #include<iostream>

 using namespace std;

 void kmeans(int n, float* xy, int k, float* cxy)

 {

     int i,j;

     for(i=;i<k;i++)

     {

         cxy[*i]=xy[*i];

         cxy[*i+]=xy[*i+];

     }

     int* mindis=(int*)malloc(n*sizeof(int));

     int* premindis=(int*)malloc(n*sizeof(int));

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

     {

         mindis[i]=-;

     }

     int change=;

     while(change)

     {

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

         {

             premindis[i]=mindis[i];

         }

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

         {

             float min=;

             for(j=;j<k;j++)

             {

                 double s=sqrt((xy[*i]-cxy[*j])*(xy[*i]-cxy[*j])+(xy[*i+]-cxy[*j+])*(xy[*i+]-cxy[*j+]));

                 if(s<min)

                 {

                     min=s;

                     mindis[i]=j;

                 }

             }

         }

         /*

         for(i=0;i<2;i++)

         {

             printf("%.3f ",cxy[2*i]);

             printf("%.3f\n",cxy[2*i+1]);

         }

         */

         for(i=;i<k;i++)

         {

             int num=;

             float s0=0.0;

             float s1=0.0;

             //cout<<i<<":";

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

             {

                 if(mindis[j]==i)

                 {

                     num++;

                     //cout<<j<<" ";

                     s0+=xy[*j];

                     s1+=xy[*j+];

                 }

             }

             if(num)

             {

                 cxy[*i]=s0/num;

                 cxy[*i+]=s1/num;

             }

             //cout<<endl;

         }

         int flag=;

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

         {

             if(mindis[i]!=premindis[i])

             {

                 flag=;

                 break;

             }

         }

         if(flag==)

             change=;

     }

 }

 int main()

 {

     float xy[]={1.0, 1.0, 2.0, 1.0, 1.0, 2.0, 4.0, 5.0, 5.0, 4.0, 4.0, 4.0};

     float cxy[]={0.0, 0.0, 0.0, 0.0};

     kmeans(,xy,,cxy);

     int i;

     for(i=;i<;i++)

     {

         printf("%.3f ",cxy[*i]);

         printf("%.3f\n",cxy[*i+]);

     }

     return ;

 }