广搜模板题

#include <bits/stdc++.h>
#include<queue>
using namespace std;
struct node{
	int x,y;
	int step;
};
int dx[] = {-2,-2,-1,-1,1,2,2,1};
int dy[] = {1,-1,2,-2,-2,-1,1,2};
int vis[1001][1001];
int n;
int stx, sty, endx, endy;
void bfs(){
	queue<node>q;
	node t;
	t.x = stx;
	t.y = sty;
	t.step = 0;
	q.push(t);
	while(!q.empty())
	{
		node e=q.front();
		q.pop();
		if(e.x == endx and e.y == endy){
			cout << e.step<<endl;
			break;
		}
		for(int i = 0; i < 8; i++){
			int nx = e.x +  dx[i];
			int ny = e.y + dy[i];
			if(nx >= 0 and nx < n and ny >= 0 and ny < n and vis[nx][ny] == 0){
				vis[nx][ny] = 1;
				node d;
				d.x = nx;
				d.y = ny;
				d.step = e.step + 1;
				q.push(d);
			}			
		}
	}
}
int main()
{
	int t;
	cin >> t;
	while(t--){
		memset(vis, 0, sizeof(vis));
		cin >> n;
		cin >> stx >> sty;
		cin >> endx >> endy;
		bfs();
	} 
	return 0;
}