BZOJ SCOI2005骑士精神

裸IDA*,ans从1到15循环来限制搜索深度。

 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 using namespace std;
 int d,s[][],ans;
 char c;
 bool flag;
 int ma[][]={{,,,,,},
               {,,,,,},
               {,,,,,},
               {,,,,,},
               {,,,,,},
               {,,,,,}},dx[]={,,,,-,-,-,-},dy[]={,,-,-,-,-,,};
 void swap(int &a,int &b){int c=a;a=b;b=c;}
 bool check()
 {
     int i,j;
     for (i=;i<=;++i)for (j=;j<=;++j)if (s[i][j]!=ma[i][j]) return ;
     return ;
 }
 bool f(int g)
 {
     int h=,i,j;
     for (i=;i<=;++i)for (j=;j<=;++j)if (s[i][j]!=ma[i][j])
     {h++; if (g+h>ans) return ;}
     return ;
 }
 void dfs(int x,int y,int g)
 {
     if (g==ans)
     {
         if (check()) flag=;
         return;
     }
     if (flag) return;
     int i,nowx,nowy;
     for (i=;i<;++i)
     {
         nowx=x+dx[i];nowy=y+dy[i];
         if ((nowx<)||(nowy<)||(nowx>)||(nowy>)) continue;
         swap(s[x][y],s[nowx][nowy]);
         if (f(g)) dfs (nowx,nowy,g+);
         swap(s[nowx][nowy],s[x][y]);
     }
 }
 int main()
 {
     int i,j,t,x,y;
     scanf("%d\n",&t);
     while (t>){t--;
         for (i=;i<=;++i)
         {
             for (j=;j<=;++j)
             {
                 c=getchar();
                 if (c=='*') s[i][j]=,x=i,y=j;
                 else s[i][j]=int(c-'');
             }
             scanf("\n");
         } flag=;
         for (ans=;ans<=;++ans)
         {
             dfs(x,y,);
             if (flag) break;
         }
         if (flag) printf("%d\n",ans);
         else printf("-1\n");
     }
     return ;
 }