Hello，everybody，我是越爱越难，最近做POJ1979，提交时总是WA，所有的测试数据都通过了，我自己又反复看了几遍代码，感觉没毛病，扎心了！望老铁们来帮我一把！以下附上我写的Java代码。

import java.util.Scanner;

public class CopyOfRedAndBlack {
    static int m,n;
    static char[][] c = new char[25][25];
    static int sum=0;
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        n = scan.nextInt();
        m = scan.nextInt();
        while(n>0&&m>0) {
            sum = 0;
            int x = -1,y = -1;
            for(int i=0; i<m; i++) {
                String s = new String("");
                s = scan.next();
                c[i] = s.toCharArray(); 
                if(x==-1) {
                    int j = s.indexOf('@');
                    if(j>0) {
                        x = i;
                        y = j;
                    }
                }
            }
            solve(x,y);
            System.out.println(sum);
            n = scan.nextInt();
            m = scan.nextInt();
        }

        scan.close();
    }

    public static void solve(int x,int y) {
        if(x>=0&&x<m&&y>=0&&y<n) {
            if(c[x][y]=='.'||c[x][y]=='@') {
                    sum++;
                    solve(x+1,y);
                    solve(x,y-1);
                    solve(x-1,y);
                    solve(x,y+1);
            }

        }
    }
}