C++-POJ1915-Knight Moves[BFS]

#include <queue>
#include <cstdio> 
#include <cstring>
using namespace std;
int vis[305][305];
int trun[8][2]={{1,2},{2,1},{1,-2},{-2,1},{-1,2},{2,-1},{-1,-2},{-2,-1}};
struct point{int x,y;point(int x=0,int y=0):x(x),y(y){}};
int bfs(point s,point t,int l){
    memset(vis,0,sizeof(vis));
    queue<int>q;q.push(s.x*1000+s.y);
    while(!q.empty()){
        point u=point(q.front()/1000,q.front()%1000);q.pop();
        if(u.x==t.x&&u.y==t.y)return vis[t.x][t.y];
        for(int i=0;i<8;i++){
            point v=point(u.x+trun[i][0],u.y+trun[i][1]);
            if(v.x>=0&&v.x<l&&v.y>=0&&v.y<l&&!vis[v.x][v.y])
                vis[v.x][v.y]=vis[u.x][u.y]+1,q.push(v.x*1000+v.y);
        }
    }
}
int main(){
    int n,l,a,b,c,d;
    for(scanf("%d",&n);n--;)
        scanf("%d%d%d%d%d",&l,&a,&b,&c,&d),printf("%d\n",bfs(point(a,b),point(c,d),l));
    return 0;
}