POJ-1979-Red and Black

#include<cstdio>
#include<cstring>
#include<iostream>
#include<queue>
using namespace std;
const int maxn=30;
char map[maxn][maxn];
int r,c,sx,sy,ans,movex[4]={1,-1,0,0},movey[4]={0,0,-1,1};
bool vis[maxn][maxn];
void DFS(int x,int y)
{
if(map[x][y]=='#')
return;
ans++;
for(int i=0;i<4;i++)
{
if(vis[x+movex[i]][y+movey[i]])
continue;
vis[x+movex[i]][y+movey[i]]=1;
DFS(x+movex[i],y+movey[i]);
}
}
int main()
{
while(scanf("%d%d",&c,&r)&&(c+r))
{
for(int i=0;i<=c+1;i++)
map[0][i]=map[r+1][i]='#';
for(int i=0;i<=r+1;i++)
map[i][0]=map[i][c+1]='#';
ans=0;
memset(vis,0,sizeof(vis));
for(int i=1;i<=r;i++)
{
getchar();
for(int j=1;j<=c;j++)
{
scanf("%c",&map[i][j]);
if(map[i][j]=='@')
sx=i,sy=j;
}
}
vis[sx][sy]=1;
DFS(sx,sy);
printf("%d\n",ans);
}
return 0;
}