Oil Deposits

#include<stdio.h>
#include<string.h>
int m,n,dir[8][2]={{-1,-1},{-1,0},{-1,1},{0,-1},{0,1},{1,-1},{1,0},{1,1}};
char grid[101][101];
bool vis[101][101];
bool in_grid(int x,int y)
{
    return x>=0&&x<=m&&y>=0&&y<n;
}
void DFS(int x,int y)
{
    vis[x][y]=true;
    for
 
(int i=0;i<8;i++)
    {
        if(in_grid(x+dir[i][0],y+dir[i][1])
           &&grid[x+dir[i][0]][y+dir[i][1]]==[email protected]
           &&!vis[x+dir[i][0]][y+dir[i][1]])
            DFS(x+dir[i][0],y+dir[i][1]);
    }
}
int main()
{
    while(~scanf("%d%d",&m,&n)&&m)
    {
        for
 
(int i=0;i<m;i++)
        {
            scanf("%s",grid[i]);
            memset(vis[i],false,sizeof(bool)*n);
        }
        int counter=0;
        for(int i=0;i<m;i++)
            for(int j=0;j<n;j++)
            {
                if(grid[i][j]==[email protected]&&!vis[i][j])
                {
                    counter++;
                    DFS(i,j);
                }
            }
        printf("
 
%d\n",counter);
    }
    return 0;
} 

HDU 1241: Oil Deposits