Solution for Surface on codingame

Solution.java

// Read inputs from System.in, Write outputs to System.out.
// Your class name has to be Solution

import java.util.*;
import java.io.*;
import java.math.*;

class Solution {
	
	static boolean[][] terrain;
	static int largeur;
	static int hauteur;
	
	private static class Point {
	    int x;
	    int y;
	    public Point(int x, int y) {
	        this.x = x;
	        this.y = y;
	    }
	    
        @Override
        public boolean equals(Object o) {
            Point point = (Point) o;
            return x == point.x && y == point.y;
        }

        @Override
        public int hashCode() {
            int result = x;
            result = 31 * result + y;
            return result;
        }
        
        public List<Point> next() {
            List<Point> result = new ArrayList<Point>();
            if (x > 0) {
                result.add(new Point(x - 1, y));
            }
            if (x < largeur-1) {
                result.add(new Point(x + 1, y));
            }
            if (y > 0) {
                result.add(new Point(x, y - 1));
            }
            if (y < hauteur-1) {
                result.add(new Point(x, y + 1));
            }
            return result;
        }
	    
	}
	
	private static void init(Scanner in) {
	    
		largeur = in.nextInt();
		hauteur = in.nextInt();in.nextLine();
		terrain = new boolean[largeur][hauteur];
		for (int y = 0; y < hauteur; y++) {
			String line = in.nextLine();
			for (int x = 0; x < largeur; x++) {
			    terrain[x][y] = false;
			    if (line.charAt(x) == 'O') {
			        terrain[x][y] = true;
			    }
			}
		}
	}

	public static void main(String args[]) {
		Scanner in = new Scanner(System.in);
		
		init(in);
		
		int nbTests = in.nextInt();
		for (int i = 0; i< nbTests; i++) {
		    int x = in.nextInt();
		    int y = in.nextInt();
		    System.out.println(tailleLac(new Point(x, y)));
		}
	}
	
	public static int tailleLac(Point point) {
	    LinkedList<Point> pointToExplore = new LinkedList<Point>();
	    Set<Point> pointExplored = new HashSet<Point>();
	    
	    pointToExplore.add(point);
	    
	    int tailleLac = 0;
	    
	    while (!pointToExplore.isEmpty()) {
	        Point next = pointToExplore.removeFirst();
	        
	        if (!pointExplored.contains(next)
	            && terrain[next.x][next.y]) {
	            tailleLac++;
	            pointExplored.add(next);
	            pointToExplore.addAll(next.next());
	        }
	    }
	    
	    return tailleLac;
	    
	}
}