Poj Solution 2941

http://poj.org/problem?id=2941

//* @author: 82638882@163.com
import java.io.*;
public class Main
{
 public static void main(String[] args) throws IOException
 {
  InputStreamReader is=new InputStreamReader(System.in);
  BufferedReader in=new BufferedReader(is);
  while(true)
  {
    String s=in.readLine();
    int a=Integer.parseInt(s);
    if(a==0)break;
    int[][] arr=new int[a][a];
    String[] ss;
    for(int i=0;i< a;i++)
    {
      ss=in.readLine().split(" ");
      for(int j=0;j< a;j++)
       arr[i][j]=Integer.parseInt(ss[j]);
    }
    boolean bb=true;
    for(int i=0;i< a-1;i++)
    {
        int k=arr[i][0]-arr[i+1][0];
        for(int j=1;j< a;j++)
        {
             if(k!=arr[i][j]-arr[i+1][j])
          {
            bb=false;
            break;
          }
        }
        if(!bb)break;
    }
    System.out.println((bb?"":"not ")+"homogeneous");
   }
 }
}