改了两个大锅依然WA最后一个点```cpp
#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;
const int inf=507;
int ans,vis[inf][inf];
char a[inf][inf];
struct node{
int x,y;
};
int n,m;
inline bool judge(int x,int y){
if(x && y && x<=n && y<=m)return true;
else return false;
}
inline void bfs(){
queue <node> q;
q.push((node){0,0});
while(!q.empty()){
node v=q.front();
q.pop();
int i=v.x,j=v.y;
if(!vis[i+1][j]&&a[i+1][j]=='0'){
vis[i+1][j]=1;
q.push((node){i+1,j});
if(judge(i+1,j))ans--;
}
if(!vis[i][j+1]&&a[i][j+1]=='0'){
vis[i][j+1]=1;
q.push((node){i,j+1});
if(judge(i,j+1))ans--;
}
if(!vis[i-1][j]&&a[i-1][j]=='0'){
vis[i-1][j]=1;
q.push((node){i-1,j});
if(judge(i-1,j))ans--;
}
if(!vis[i][j-1]&&a[i][j-1]=='0'){
vis[i][j-1]=1;
q.push((node){i,j-1});
if(judge(i,j-1))ans--;
}
}
}
int main(){
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++){
a[i][0]='0';
a[i][m+1]='0';
}
for(int i=1;i<=m;i++){
a[0][i]='0';
a[n+1][i]='0';
}
for(int i=1;i<=n;i++)
for(int j=1;j<=m;j++){
cin>>a[i][j];
if(a[i][j]=='0')ans++;
}
bfs();
cout<<ans;
return 0;
}
```
by _RedForest @ 2019-02-27 20:10:21
改了两个大锅依然WA最后一个点
```cpp
// luogu-judger-enable-o2
#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;
const int inf=507;
int ans,vis[inf][inf];
char a[inf][inf];
struct node{
int x,y;
};
int n,m;
inline bool judge(int x,int y){
if(x && y && x<=n && y<=m)return true;
else return false;
}
inline void bfs(){
queue <node> q;
q.push((node){0,0});
while(!q.empty()){
node v=q.front();
q.pop();
int i=v.x,j=v.y;
if(!vis[i+1][j]&&a[i+1][j]=='0'){
vis[i+1][j]=1;
q.push((node){i+1,j});
if(judge(i+1,j))ans--;
}
if(!vis[i][j+1]&&a[i][j+1]=='0'){
vis[i][j+1]=1;
q.push((node){i,j+1});
if(judge(i,j+1))ans--;
}
if(!vis[i-1][j]&&a[i-1][j]=='0'){
vis[i-1][j]=1;
q.push((node){i-1,j});
if(judge(i-1,j))ans--;
}
if(!vis[i][j-1]&&a[i][j-1]=='0'){
vis[i][j-1]=1;
q.push((node){i,j-1});
if(judge(i,j-1))ans--;
}
}
}
int main(){
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++){
a[i][0]='0';
a[i][m+1]='0';
}
for(int i=1;i<=m;i++){
a[0][i]='0';
a[n+1][i]='0';
}
for(int i=1;i<=n;i++)
for(int j=1;j<=m;j++){
cin>>a[i][j];
if(a[i][j]=='0')ans++;
}
bfs();
cout<<ans;
return 0;
}
```
by _RedForest @ 2019-02-27 20:11:22