可以考虑在bfs的时候将最短步数记下，这样bfs一次就行
by Geoyster @ 2023-05-14 10:21:03
@[tiaotiao0830](/user/542893) 您的 $bfs$ 码风好奇怪
```cpp
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
int n,m,bx,by,dis[410][410];
int b[8][2] = {{2,1},{1,2},{-2,1},{-1,2},{2,-1},{1,-2},{-2,-1},{-1,-2}};
void bfs(int bx,int by)
{
memset(dis,-1,sizeof(dis));
queue<int> qx,qy;
qx.push(bx);
qy.push(by);
dis[bx][by] = 0;
while(!qx.empty())
{
int x = qx.front(),y = qy.front();
qx.pop();
qy.pop();
for(int i = 0;i <= 7;i++)
{
int nx = x + b[i][0],ny = y + b[i][1];
if (nx <= 0 || nx > n || ny <= 0 || ny > m) continue;
if (dis[nx][ny] > -1) continue;
dis[nx][ny] = dis[x][y] + 1;
qx.push(nx);
qy.push(ny);
}
}
}
int main()
{
cin >> n >> m;
cin >> bx >> by;
bfs(bx,by);
for (int i = 1;i <= n;i++)
{
for (int j = 1;j <= m;j++)
{
printf("%5d",dis[i][j]);
}
cout << endl;
}
return 0;
}
```
by codejiahui @ 2023-05-14 10:23:46