0714c

/*************************************************************************
> File Name: code/2015summer/0714/C_DFS.cpp
> Author: 111qqz
> Email: [email protected]
> Created Time: 2015年07月15日 星期三 08时59分30秒
************************************************************************/

#include<iostream>
#include<iomanip>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<string>
#include<map>
#include<set>
#include<queue>
#include<vector>
#include<stack>
using namespace std;
#define REP(i, n) for (int i=0;i<int(n);++i)
typedef long long LL;
typedef unsigned long long ULL;
const int N=50;
char ch[N][N];
int n,m,sx,sy,ans;
int dirx[4]={0,1,0,-1};
int diry[4]={1,0,-1,0};
bool vis[N][N];

bool ok(int xx,int yy)
{
if (xx>=0&&xx<n&&yy>=0&&yy<m&&ch[xx][yy]==‘.‘&&vis[xx][yy]==false)
return true;
return false;
}
void dfs(int x,int y)
{
for ( int i = 0 ; i < 4 ; i++ )
{
int newx=x+dirx[i];
int newy=y+diry[i];
if (ok(newx,newy))
{
ans++;
vis[newx][newy]=true;
dfs(newx,newy);
}
}
}
int main()
{
while (scanf("%d %d",&m,&n)!=EOF&&n&&m)
{
memset(vis,false,sizeof(vis));
ans = 0;
getchar();
for ( int i = 0 ; i < n ; i++ )
for ( int j = 0 ; j < m ; j++ )
{
scanf("%c",&ch[i][j]);
if (ch[i][j]==‘@‘)
{
sx = i;
sy = j;
}
getchar();

}
dfs(sx,sy);
cout<<ans<<endl;
}
return 0;
}