UVa 572 - Oil Deposits 【DFS】联通块问题

#include <stdio.h>             
#include <string.h>
char map[110][110];
int vis[110][110];
int n, m, ans;
int dir[8][2] = { {0,1},{1,1},{1,0},{1,-1},{0,-1},{-1,-1},{-1,0},{-1,1} };
void dfs(int a,int b)
{
    int i, j;
    vis[a][b] = 1;
    if (a > m || b > n || a < 1 || b < 1)return;
    for (int k = 0; k < 8; k++)
    {
        int x = a + dir[k][0];
        int y = b + dir[k][1];
        if (x < 1 || y<1 || x>m || y>n)continue;
        if (map[x][y] == ‘@‘&&vis[x][y] == 0)
        {
            dfs(x, y);
        }
    }
}

int main()
{
    int i, j;
    while (scanf("%d%d", &m, &n)!= EOF, n || m)
    {
        getchar();
        for (i = 1; i <= m; i++)
        {
            scanf("%s", map[i]+1);           
        }
        memset(vis, 0, sizeof(vis));
        ans = 0;
        for (i = 1; i <=m; i++)
        {
            for (j = 1; j <=n; j++)
            {
                if (map[i][j] == ‘@‘&&vis[i][j] == 0)
                {
                    ans++;
                    dfs(i, j);
                }
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}