//位压缩加搜索枚举，用pre记录其前驱#include
     
      #include
      
       #define N 100000struct node{    int x,y,num,pre,step;}p[N*4];struct nn{    int x,y;}g[N*4];char str[10][10];int vis[N];int d[16]={    0xf888,0xf444,0xf222,0xf111,    0x8f88,0x4f44,0x2f22,0x1f11,    0x88f8,0x44f4,0x22f2,0x11f1,    0x888f,0x444f,0x222f,0x111f,};int bfs(int sum){    int head=0,tail=0,i;    p[head].num=sum;    p[head].step=0;    p[head].pre=0;    tail++;    while(head
       
        =0;i--)    {        printf("%d %d\n",g[i].x+1,g[i].y+1);    }}