求修改 开o2 TLE两个，万分感谢！！！

#include <bits/stdc++.h>
using namespace std;
int vist[405][405],n,m,x,y;
int xk[8]={1,2,2,1,-1,-2,-2,-1};
int yk[8]={2,1,-1,-2,-2,-1,1,2};
struct lou{
	int x,y;
	int bu;
};
queue<lou>dui;
int bfs(int a,int b){
	while(!dui.empty()){
		dui.pop();
	}
	memset(vist,0,sizeof(vist));
	struct lou cur,now;
	cur.x=x;cur.y=y;cur.bu=0;
	dui.push(cur);
	vist[x][y]=1;
	while(dui.empty()==false){
		now=dui.front();
		dui.pop();
		if(now.x==a&&now.y==b){
			return now.bu;
		}
		int xx,yy;
		for(int p=0;p<8;p++){
			xx=now.x+xk[p];
			yy=now.y+yk[p];
			if(xx>=1&&xx<=n&&yy>=1&&yy<=m&&vist[xx][yy]==0){
				//cout<<xx<<"----"<<yy<<"   ";
				vist[xx][yy]=1;
				cur.x=xx;cur.y=yy;
				cur.bu=now.bu+1;
				dui.push(cur);
			}
		}			
	}
	return -1;
}
int main(){
	cin>>n>>m>>x>>y;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			printf("%-5d",bfs(i,j));
		}
		cout<<endl;
	}
	return 0;
}