HUD 1312 Red and Black(用深搜写的)

#include <iostream>

using namespace std;



char g[25][25];

int dir[4][2] = {0, 1, 0, -1, 1, 0, -1, 0};

int sum;

int n, m;



void Dfs(int x, int y)

{

    int a, b;

    for (int i = 0; i < 4; i++)

    {

        a = x + dir[i][0];

        b = y + dir[i][1];

        if (a >= 1 && a <= n && b >= 1 && b <= m && g[a][b] == '.')

        {

            sum++;

            g[a][b] = '#';

            Dfs(a, b);

        }

    }

}

int main()

{



    int star_x, star_y;

    while (scanf("%d%d", &m, &n), n + m)

    {

        for (int i = 1; i <= n; i++)

        {

            for (int j = 1; j <= m; j++)

            {

                scanf(" %c", &g[i][j]);

                if (g[i][j] == '@')

                {

                    g[i][j] = '#';

                    star_x = i;

                    star_y = j;

                }

            }

        }

        sum = 1;

        Dfs(star_x, star_y);

        printf("%d\n", sum);

    }



    return 0;

}