import java.util.*;
import java.lang.*;
import java.io.*;

class Main {
     public static void showSandPile(int[][] pile){
        System.out.println("Affichage du grid : ");
        for(int i=0; i<pile.length; i++){
            for(int j=0; j<pile[i].length; j++){
                System.out.print(pile[i][j]);
            }
            System.out.println();
        }
    }
    
    public static boolean updateSandPile(int[][] pile){
        boolean startAgain = false;
        for(int i=0; i<pile.length; i++){
            for(int j=0; j<pile[i].length; j++){
                if(pile[i][j] >= 4){
                    int value = 0;
                    value = Math.max(value, pile[i][j]-=4) ;
                    if(i-1 >=0)
                        value = Math.max(value, pile[i-1][j]+=1);
                    if(j-1 >=0)
                        value = Math.max(value, pile[i][j-1]+=1);
                    if(j+1 < pile[i].length)
                        value = Math.max(value, pile[i][j+1]+=1);
                    if(i+1 < pile[i].length)
                        value = Math.max(value, pile[i+1][j]+=1);  
                    if(value >= 4){
                        startAgain = true;
                    }
                }
            }
        }
        return startAgain;
    }
    
    public static int [][] sandPile(int[][] pile, int n){
        System.out.println("--Sand Pile--");
        
        showSandPile(pile);
        
        System.out.println("Ajout de " + n + " grain(s) de sable");
        int middle = (pile.length/2);
        //System.out.println("Ancienne valeur : " + pile[middle][middle]);
        pile[middle][middle]+=n;
       
       boolean startAgain = true;
       int k=0;
       while(startAgain){
            k++;
            //System.out.println("Tentative : " + k);
            startAgain = updateSandPile(pile);
       }
       return pile;
    }

    public static void main(String[] args) {
        int [][] pile;
        pile = sandPile(new int[][] {
            {1,1,1},
            {1,3,1},
            {1,1,1}
        },1);
        showSandPile(pile);
        
        pile = sandPile(new int[][] {
        {0,0,3,0,0},
        {0,0,3,0,0},
        {3,3,3,3,3},
        {0,0,3,0,0},
        {0,0,3,0,0},
        },5);
        showSandPile(pile);
        
        pile = sandPile(new int[][] {
        {0,0,0,0,0},
        {0,0,0,0,0},
        {0,0,16,0,0},
        {0,0,0,0,0},
        {0,0,0,0,0},
        },0);
        showSandPile(pile);
    }
}