@[thehanged](/user/638272)
```cpp
#include <iostream>
using namespace std;
const int N = 25;
bool st[N][N];
char map[N][N];
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
int n, m, ans = 1;
void dfs(int x, int y){
st[x][y] = true;
for(int i = 0; i < 4; ++ i){
int tx = x + dx[i], ty = y + dy[i];
if(tx <= 0 || tx > n || ty <= 0 || ty > m) continue;
if(map[tx][ty] == '.' && !st[tx][ty]){ // 可以走的地方
ans ++;
dfs(tx, ty);
}
}
}
int main(){
scanf("%d %d", &m, &n);
int x, y;
for(int i = 1; i <= n; ++ i){
for(int j = 1; j <= m; ++ j){
std::cin>>map[i][j];
if(map[i][j] == '@') x = i, y = j;
}
}
dfs(x, y);
printf("%d", ans);
// for(int i = 1; i <= n; ++ i){
// for(int j = 1; j <= m; ++ j){
// putchar(map[i][j]);
// }
// puts("");
// }
return 0;
}
```
这样就可以过了
by nightwatch_ryan @ 2024-04-25 22:22:12
<https://www.luogu.com.cn/paste/cb7doh5c>
by Terrible @ 2024-04-25 22:45:48
@[Terrible](/user/195942) 猜到了，洛谷没有进行特殊处理，一般来说评测机全部都是LF（Linux），洛谷不仅有CR还有CRLF，这真的太无语了
by thehanged @ 2024-04-26 12:20:48