@[QAQ_juruo](/user/1098781)
```cpp
#include<bits/stdc++.h>
using namespace std;
int dx[8]={1,2,2,1,-1,-2,-2,-1};
int dy[8]={-2,-1,1,2,2,1,-1,-2};
int n,m,x,y,ans[1005][1005];
bool vis[1005][1005];
struct node{
int x,y;
};
queue<node> q;
void bfs(int x,int y){
q.push(node{x,y});
vis[x][y]=1;
ans[x][y]=0;
while(!q.empty()){
node now=q.front();
q.pop();
for(int i=0;i<8;i++){
int tx=now.x+dx[i];
int ty=now.y+dy[i];
if(tx>=1 && tx<=n && ty<=m && ty>=1 && !vis[tx][ty]){
vis[tx][ty]=1;
ans[tx][ty]=ans[now.x][now.y]+1;
q.push(node{tx,ty});
}
}
}
}
int main(){
cin>>n>>m>>x>>y;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
ans[i][j]=-1;
}
}
bfs(x,y);
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
printf("%-5d",ans[i][j]);
}
printf("\n");
}
return 0;
}
```
by wei2013 @ 2024-02-10 09:46:40
@[QAQ_juruo](/user/1098781)
```cpp
vis[400+1][400+1]={-1}
```
这行相当于是吧第0项化为-1
by wei2013 @ 2024-02-10 09:48:13
@[wei2013](/user/1060672) thanks
by QAQ_juruo @ 2024-02-15 16:24:34