C++-POJ1915-Knight Moves[BFS]

 1 #include 
 2 #include  
 3 #include 
 4 using namespace std;
 5 int vis[305][305];
 6 int trun[8][2]={{1,2},{2,1},{1,-2},{-2,1},{-1,2},{2,-1},{-1,-2},{-2,-1}};
 7 struct point{int x,y;point(int x=0,int y=0):x(x),y(y){}};
 8 int bfs(point s,point t,int l){
 9     memset(vis,0,sizeof(vis));
10     queue<int>q;q.push(s.x*1000+s.y);
11     while(!q.empty()){
12         point u=point(q.front()/1000,q.front()%1000);q.pop();
13         if(u.x==t.x&&u.y==t.y)return vis[t.x][t.y];
14         for(int i=0;i<8;i++){
15             point v=point(u.x+trun[i][0],u.y+trun[i][1]);
16             if(v.x>=0&&v.x=0&&v.yvis[v.x][v.y])
17                 vis[v.x][v.y]=vis[u.x][u.y]+1,q.push(v.x*1000+v.y);
18         }
19     }
20 }
21 int main(){
22     int n,l,a,b,c,d;
23     for(scanf("%d",&n);n--;)
24         scanf("%d%d%d%d%d",&l,&a,&b,&c,&d),printf("%d\n",bfs(point(a,b),point(c,d),l));
25     return 0;
26 }