Envío 5791

Código

import java.io.*;
import java.util.StringTokenizer;

class Main
{
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        st = new StringTokenizer(br.readLine());
        int filascolumnas = Integer.parseInt(st.nextToken());
        int matriz[][] = new int[filascolumnas][filascolumnas]; 
        int columnas = 0;
        int filas = 0;
        int di = 0;
        int dd = 0;
        
        for(int i=0;i<filascolumnas;i++){
            st = new StringTokenizer(br.readLine());
            for(int j=0;j<filascolumnas;j++){
                matriz[i][j]=Integer.parseInt(st.nextToken());    
            }
        }
        
        for(int i=0;i<filascolumnas;i++){
            for(int j=0;j<filascolumnas;j++){
                filas+=matriz[i][j];
                columnas+=matriz[j][i];
                if(i==j){
                    di+=matriz[i][j];
                    dd+=matriz[i][filascolumnas-j-1];
                }
            }
        }
        
        if(filas/filascolumnas+columnas/filascolumnas+di+dd==di*4){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
    }
}