Ốc sên ăn rau

import java.util.Scanner;
public class OcSenAnRau {

    static class toaDo
    {
        int x;
        int y;
        public toaDo(int x, int y)
        {
            this.x=x;
            this.y=y;
        }
    }
    static class Queue
    {
        final int size=100;
        toaDo [] q;
        int front, rear;
        //Constructor
        public Queue()
        {
            q=new toaDo[size];
            front=rear=-1;
        }
        public boolean isEmpty()
        {
            if(rear==front) return true;
            return false;
        }
        public void enQueue(toaDo a)
        {
            rear=(rear+1)%size;
            q[rear]=a;
        }
        public toaDo deQueue()
        {
            front=(front+1)%size;
            return q[front];
        }
    }
    public static int[]X= {-1,1,0,0};
    public static int[]Y= {0,0,-1,1};
    public static void main(String[] args) throws FileNotFoundException {
        System.setIn(new FileInputStream("D:\\Program\\STP\\senRau.txt"));
        Scanner sc=new Scanner(System.in);
        int m,n,res=1;
        m=sc.nextInt();
        n=sc.nextInt();
        int x=sc.nextInt();
        int y=sc.nextInt();
        int [][]A=new int[m][n];
        for(int i=0;i<m;i++)
        {
            for(int j=0;j<n;j++)
            {
                A[i][j]=sc.nextInt();
            }
        }
        Queue QQ=new Queue();
        A[x-1][y-1]=1;
        QQ.enQueue(new toaDo(x-1, y-1));
        while(!QQ.isEmpty())
        {
            toaDo tmpt=QQ.deQueue();
            for(int i=0;i<4;i++)
            {
                int u=tmpt.x+X[i];
                int v=tmpt.y+Y[i];
                if(u>=0&&u<m&&v>=0&&v<n&&A[u][v]==0)
                {
                    res++;
                    QQ.enQueue(new toaDo(u, v));
                    A[u][v]=1;
                }
            }
        }
        System.out.println(res);
    }

}