POJ-1324 Holedox Moving

Question: Snake

Train of Thought: BFS + status record, pitfall countless posts,

#include
 
  #include
  
   #include
   
    using namespace std;const int MAXN = 500000;bool flag[8],vis[25][25],mp[21][21][16384];int n,m,l;int xx[4]={-1,0,1,0}; // up,right,dow,leftint yy[4]={0,1,0,-1};int front,rear;struct Node{int x,y;int step;int s[8];int p[8][2];};Node q[MAXN];int _pre(int sx,int sy,int _x,int _y){int x=_x-sx,y=_y-sy;if(x==-1) return 0;else if(x==1) return 2;else if(y==-1) return 1;return 3;}int adss(Node G){int va=G.s[0],vb=1,i;for(i=1;i
    
     =n || y>=m || vis[x][y]) continue;if(itself(x,y,q[front])) continue;rear=(rear+1)%MAXN;q[rear].x=x,q[rear].y=y,q[rear].step=q[front].step+1;for(int j=0;j