acwing 188 武士风度的牛

#include<iostream>
#include<algorithm>
#include<cstring>
#include<queue>
 
using namespace std ;
const int N = 200 ;
char g[N][N] ;
int n , m ;
int fx,fy ; 
int hx,hy ;
struct node{
  int x , y ;
  node(int xx ,int yy){
    x = xx , y = yy ;
  }
};
int d[8][2]= {{-2,1},{-1,2},{1,2},{2,1},{2,-1},{1,-2},{-1,-2},{-2,-1}};
queue<node> q ;
int dis[N][N] ;
void bfs(){
  q.push(node(fx,fy)) ;
  dis[fx][fy] = 0 ;
  while(!q.empty()){
    node now = q.front() ;
    q.pop() ;
    int x = now.x , y = now.y ;
    if(x == hx && y == hy) return ;
    for(int i = 0 ; i < 8 ; i ++){
      int tx = x + d[i][0] , ty = y + d[i][1] ;
      if(tx<0||tx>=n||ty<0||ty>=m||dis[tx][ty]!=-1||g[tx][ty] == '*') continue ;
      q.push(node(tx,ty)) ;
      dis[tx][ty] = dis[x][y] + 1 ;
    }
  }
}
int main(){
  cin >> m >> n ;
  memset(dis,-1,sizeof(dis)) ;
  for(int i = 0 ; i < n ;i ++){
    for(int j = 0 ; j < m ;j ++){
      cin >> g[i][j] ;
      if(g[i][j] == 'K') fx = i , fy = j ;
      if(g[i][j] == 'H') hx = i , hy = j ;
    }
  }
  bfs() ;
  cout << dis[hx][hy] << endl ;
}