POJ 3009 Curling 2.0

POJ 3009 Curling 2.0

简单的迭代加深搜索求最优解。注意判断可以继续行走的条件。
以下是我的代码：

/*
 * Author:  lee1r
 * Created Time:  2011/8/6 8:51:53
 * File Name: poj3009.cpp
  */
#include < iostream >
#include < sstream >
#include < fstream >
#include < vector >
#include < list >
#include < deque >
#include < queue >
#include < stack >
#include < map >
#include < set >
#include < bitset >
#include < algorithm >
#include < cstdio >
#include < cstdlib >
#include < cstring >
#include < cctype >
#include < cmath >
#include < ctime >
#define  L(x) ((x)<<1)
#define  R(x) (((x)<<1)+1)
#define  Half(x) ((x)>>1)
#define  lowbit(x) ((x)&(-(x)))
using   namespace  std;
const   int  kInf( 0x7f7f7f7f );
const   double  kEps(1e - 8 );
typedef  long   long  int64;
typedef unsigned  long   long  uint64;

const   int  kMaxn( 27 );
const   int  dx[] = { 1 , - 1 , 0 , 0 },dy[] = { 0 , 0 , - 1 , 1 };

int  n,m,s1,s2,g1,g2,r[kMaxn][kMaxn];
bool  success;

int  Check( int  x, int  y, int  dir, int   & xx, int   & yy)
{
     int  t( 0 );
     do
    {
         if (r[x][y] == 3 )
        {
            xx = x;
            yy = y;
             return   3 ;
        }
         else   if (t <= 1   &&  r[x][y] == 1 )
             return   0 ;
         else   if (t > 1   &&  r[x][y] == 1 )
        {
            xx = x;
            yy = y;
             return   1 ;
        }
        x += dx[dir];
        y += dy[dir];
        t ++ ;
    } while (x >= 1   &&  x <= n  &&  y >= 1   &&  y <= m);
     return   0 ;
}

void  dfs( int  depth, int  x, int  y, int  maxdepth)
{
     if (depth > maxdepth)
    {
         if (g1 == x  &&  g2 == y)
            success = true ;
         return ;
    }
     for ( int  i = 0 ;i < 4 ;i ++ )
    {
         int  newx,newy,result(Check(x,y,i,newx,newy));
         if (result == 1 )
        {
            r[newx][newy] = 0 ;
            dfs(depth + 1 ,newx - dx[i],newy - dy[i],maxdepth);
            r[newx][newy] = 1 ;
        }
         else   if (result == 3 )
            dfs(depth + 1 ,newx,newy,maxdepth);
    }
}

int  main()
{
     // freopen("data.in","r",stdin);
    
     while (scanf( " %d%d " , & m, & n) == 2   &&  (n  ||  m))
    {
         for ( int  i = 1 ;i <= n;i ++ )
             for ( int  j = 1 ;j <= m;j ++ )
            {
                scanf( " %d " , & r[i][j]);
                 if (r[i][j] == 2 )
                {
                    s1 = i;s2 = j;
                }
                 else   if (r[i][j] == 3 )
                {
                    g1 = i;g2 = j;
                }
            }
        
         int  ans;
        success = false ;
         for (ans = 1 ;ans <= 10 ;ans ++ )
        {
            dfs( 1 ,s1,s2,ans);
             if (success)
                 break ;
        }
        
         if (ans > 10 )
            printf( " %d\n " , - 1 );
         else
            printf( " %d\n " ,ans);
    }
    
     return   0 ;
}