hdu 1198 Farm Irrigation dfs

#include <stdio.h>

int n,m,ans;
int dir[4][2]={-1,0,0,-1,0,1,1,0};//上左右下
int ar[12][4]={{1,1,0,0},{1,0,1,0},{0,1,0,1},{0,0,1,1},
           {1,0,0,1},{0,1,1,0},{1,1,1,0},{1,1,0,1},
           {0,1,1,1},{1,0,1,1},{1,1,1,1}};
char map[55][55];

void dfs(int x,int y,int a)
{
    int i,j,b,row,col;
    map[x][y]='*';
    for (i=0;i<4;i++)
    {
        if(ar[a][i])
        {
            row=dir[i][0]+x;
            col=dir[i][1]+y;
            if(row>=0&&col>=0&&row<n&&col<m&&map[row][col]!='*')
            {
                b=map[row][col]-'A';
                if(ar[b][3-i])dfs(row,col,b);
            }
        }
    }
}

int main()
{
    int i,j;
    while (scanf("%d%d",&n,&m)!=EOF)
    {
        if(n==-1&&m==-1)break;
        for (i=0;i<n;i++)scanf("%s",map[i]);
        ans=0;
        for (i=0;i<n;i++)
        {
            for (j=0;j<m;j++)
            {
                if(map[i][j]!='*')
                {
                    ans++;
                    dfs(i,j,map[i][j]-'A');
                }
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}