HDU 1175 连连看

HDU 1175 连连看

主要在于判断转折了几次。
以下是我的代码：

#include < iostream >
#include < cstdio >
#include < cstring >
#include < ctime >
using   namespace  std;
const   int  kMaxn  =   1007 ;
const   int  dx[] = { - 1 , 0 , 1 , 0 },dy[] = { 0 , 1 , 0 , - 1 };

int  n,m,map[kMaxn][kMaxn];
bool  used[kMaxn][kMaxn];
int  x1,y1,x2,y2;

bool  dfs( int  nowx, int  nowy, int  lastx, int  lasty, int  turn_times)
{
     if (turn_times > 2 )
         return   false ;
     if (nowx == x2  &&  nowy == y2)
         return   true ;
    used[nowx][nowy] = true ;
     for ( int  i = 0 ;i < 4 ;i ++ )
    {
         int  newx(nowx + dx[i]),newy(nowy + dy[i]);
         if (newx < 1   ||  newx > n  ||  newy < 1   ||  newy > m)
             continue ;
         if (used[newx][newy])
             continue ;
         if (map[newx][newy]  &&  (newx != x2  ||  newy != y2))
             continue ;
         if ((lastx == nowx  &&  nowx == newx)  ||  (lasty == nowy  &&  nowy == newy))
        {
             if (dfs(newx,newy,nowx,nowy,turn_times))
                 return   true ;
        }
         else
        {
             if (dfs(newx,newy,nowx,nowy,turn_times + 1 ))
                 return   true ;
        }
    }
    used[nowx][nowy] = false ;
     return   false ;
}

int  main()
{
     /*
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
    // */
    
     while (cin >> n >> m  &&  (n  ||  m))
    {
         for ( int  i = 1 ;i <= n;i ++ )
             for ( int  j = 1 ;j <= m;j ++ )
                cin >> map[i][j];
         int  question_num;
        cin >> question_num;
         while (question_num -- )
        {
            cin >> x1 >> y1 >> x2 >> y2;
             if ( ! map[x1][y1]  ||   ! map[x2][y2]  ||  map[x1][y1] != map[x2][y2])
            {
                cout << " NO " << endl;
                 continue ;
            }
            memset(used, false ,kMaxn * kMaxn * sizeof ( bool ));
             if (dfs(x1,y1,x1,y1, 0 ))
                cout << " YES " << endl;
             else  cout << " NO " << endl;
        }
    }
     /*
    cout<<static_cast<double>(clock())/CLOCKS_PER_SEC<<endl;
    // */
    
return   0 ;
}