poj 1979

#include <iostream>#include <fstream>#include <cstdio>#include <cstring>using namespace std;const int MAXN=30;int vis[MAXN][MAXN];char maze[MAXN][MAXN];int sx,sy;int counter;void DFS(int x,int y){    if(vis[x][y] || maze[x][y]=='#')return;    vis[x][y]=1;    counter++;    DFS(x-1,y);    DFS(x,y-1);    DFS(x+1,y);    DFS(x,y+1);}int main(){    //cout << "Hello world!" << endl;    freopen("input","r",stdin);    int w,h;    while(scanf("%d %d",&w,&h)==2)    {        memset(vis,0,sizeof(vis));        memset(maze,'#',sizeof(maze));        counter=0;        if(w==0 || h==0)break;        for(int i=1;i<=h;i++)        {            for(int j=1;j<=w;j++)            {                cin>>maze[i][j];                if(maze[i][j]=='@')                {                    sx=i;                    sy=j;                }            }        }        //        /*        cout<<endl<<endl;        for(int i=0;i<=h+1;i++)        {            for(int j=0;j<=w+1;j++)            {                cout<<maze[i][j]<<" ";            }            cout<<endl;        }        */        DFS(sx,sy);        cout<<counter<<endl;    }    fclose(stdin);    return 0;}