poj 1915 Knight Moves

 1 #include<iostream>
 2 #include<queue>
 3 #include<cstring>
 4 using namespace std;
 5 int s;
 6 struct point{
 7     bool ex;
 8     int step;
 9 };
10 point m[300+5][300+5];
11 int d[8][2]={{-1,-2},{-2,-1},{-2,1},{-1,2},{1,2},{2,1},{2,-1},{1,-2}};
12 bool check(int x,int y){
13     if(x<0||x>=s||y<0||y>=s||m[x][y].ex)
14     return true;
15     return false;
16 }
17 int main(){
18     int n,sx,sy,ex,ey;
19     cin>>n;
20     while(n--){
21         cin>>s;
22         cin>>sx>>sy;
23         cin>>ex>>ey;
24         memset(m,false,sizeof(m));
25         m[sx][sy].ex=true;
26         m[sx][sy].step=0;
27         queue<int> q;
28         q.push(sx*1000+sy);
29         int t=0;
30         while(!q.empty()){
31             int x=q.front()/1000;
32             int y=q.front()%1000;
33             q.pop();
34             if(x==ex&&y==ey){
35                 break;
36             }
37             int i=0;
38             for(;i<8;i++){
39                 int xx=x+d[i][0];
40                 int yy=y+d[i][1];
41                 if(check(xx,yy)){
42                     continue;
43                 }
44                 q.push(xx*1000+yy);
45                 m[xx][yy].ex=true;
46                 m[xx][yy].step=m[x][y].step+1;
47             }
48         }
49         cout<<m[ex][ey].step<<endl;            
50     }
51     return 0;
52 }