(SOJ) check if a word is on a given Boggle board

该题目的大意是：给定一个4X4的字母表，按照Boggle的原则查找一个字符串是否在字母表中。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <queue>
#include <deque>
#include <map>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <iomanip>
#include <fstream>
using namespace std ;

/******************************************************************************/
class BoggleBoard {
public:
BoggleBoard ( string inputfile ) ;//¸ù¾ÝÎļþ¹¹½¨×Ö·ûÅÌ£¨grid£©
BoggleBoard ( int n , int m ) ; //Ëæ»ú¹¹½¨nÐÐmÁÐ×Ö·ûÅÌ
void printBoard () ;
char get ( int i , int j ) ;//È¡µÃ(i,j)µÄ×Ö·û
int rows () ; //·µ»Ø×Ö·ûÅÌÐÐÊý
int cols () ; //·µ»Ø×Ö·ûÅÌÁÐÊý
vector < vector <char> > grid ;
private :
int row , column ;
};

BoggleBoard::BoggleBoard ( string inputfile ) //¸ù¾ÝÎļþ¹¹½¨×Ö·ûÅÌ£¨grid£©
{
grid.clear() ;
row = 0 ;
column = 0 ;
ifstream inp ( inputfile.c_str() ) ;
string str ;
int validColumns = 0 ;
vector <char> temp ;
temp.clear() ;
while ( inp >> str )
{
if ( validColumns && validColumns != str.size() )
{
cout << "The format of file is invalid!!!" << endl ;
exit ( 1 ) ;
}
validColumns = str.size() ;
grid.push_back ( temp ) ;
for ( int j = 0 ; j < validColumns ; j ++ )
grid[row].push_back( str[j] ) ;
row ++ ;
}
column = validColumns ;
inp.close () ;
}

BoggleBoard::BoggleBoard ( int n = 4 , int m = 4 ) //Ëæ»ú¹¹½¨nÐÐmÁÐ×Ö·ûÅÌ
{
grid.clear() ;
vector <char> temp ( m ) ;
grid.resize( n , temp ) ;
row = n ;
column = m ;
srand ( time (0) ) ;
for ( int i = 0 ; i < n ; i ++ )
for ( int j = 0 ; j < m ; j ++ )
grid[i][j] = rand() % 26 + 'A' ;
}

void BoggleBoard::printBoard ()
{
cout << "The board is: " << endl ;
for ( int i = 0 ; i < row ; i ++ )
{
for ( int j = 0 ; j < column; j ++ )
{
cout << grid[i][j] ;
}
cout << endl ;
}
}

char BoggleBoard::get ( int i , int j ) //È¡µÃ(i,j)µÄ×Ö·û
{
if ( i >= 0 && i < row && j >= 0 && j < column )
return grid[i][j] ;
cout << i << " " << j << endl ;
cout << "¡¾false¡¿" << endl ;
exit(1) ;
}

int BoggleBoard::rows () //·µ»Ø×Ö·ûÅÌÐÐÊý
{
return row ;
}

int BoggleBoard::cols () //·µ»Ø×Ö·ûÅÌÁÐÊý
{
return column ;
}
/******************************************************************************/

bool isOnBoard ( BoggleBoard board , string w )
{
if ( w == "" )
return true ;
int dir[8][2] = { {1,0} , {1,1} , {0,1} , {-1,1} , {-1,0} , {-1,-1} , {0,-1} , {1,-1} }; // ¿É×ß·½Ïò
int rows = board.rows() , columns = board.cols() ;
for ( int i = 0 ; i < rows ; i ++ )
{
for ( int j = 0 ; j < columns ; j ++ )
{
if ( board.get( i , j ) == w[0] )
{
set < pair <int,int> > ss ;
ss.clear() ;
int row = i , column = j ;
ss.insert( make_pair ( i , j ) ) ;
queue < set < pair <int,int> > > path ;
while ( ! path.empty() )
path.pop() ;
path.push ( ss ) ;
queue < pair < int , pair <int,int > > > q ;
while ( ! q.empty() )
q.pop() ;
pair < int , pair <int,int > > temp = make_pair ( 1 , make_pair ( i , j ) ) ;
q.push( temp ) ;
while ( ! q.empty() )
{
temp = q.front() ;
q.pop() ;
int index = temp.first , xx = temp.second.first , yy = temp.second.second ;
ss = path.front() ;
path.pop() ;
if ( index == w.size() )
return true ;
for ( int k = 0 ; k < 8 ; k ++ )
{
set < pair <int,int> > sss = ss ;
int x = xx + dir[k][0] , y = yy + dir[k][1] ;
if ( x >= 0 && x < rows && y >= 0 && y < columns )
{
set < pair <int,int> >::iterator it = sss.find( make_pair ( x , y ) ) ;
if ( it != sss.end() )
continue ;
if ( board.get( x , y ) == w[index] )
{
q.push( make_pair ( index + 1 , make_pair ( x , y ) ) ) ;
sss.insert( make_pair ( x , y ) ) ;
path.push( sss ) ;
}
}
}
}
}
}
}
return false ;
}

int main ()
{
BoggleBoard a ( "grid1.txt" ) ;
cout << isOnBoard ( a , "LTVL" ) << endl ;
cout << isOnBoard ( a , "ETR" ) << endl ;
cout << isOnBoard ( a , "HHGTH" ) << endl ;
return 0 ;
}