百度编程大赛的9宫图代码及解析

//author:1025679612@qq.com

//csdn:http://blog.csdn.net/wind_2008_06_29/article/details/7706531

#include <iostream>
#include <list>
using std::cout;
using std::endl;
using std::cin;
using std::list;

bool	bVisitTag[387420489]=	{false};	//9^9用来表示其中的一种状态是否被访问过

//=========================================================================
//begin class	Point	define
//=========================================================================
class	Point{
public:
Point();
Point(const	Point&	rhs);
public:
bool	operator==(const	Point&	rhs);
bool	operator!=(const	Point&	rhs);
Point&	operator= (const	Point&	rhs);
public:
int		m_iRow;		//
int		m_iCol;
};

Point::Point(){}

Point::Point(const	Point&	rhs){
m_iRow		=rhs.m_iRow;
m_iCol		=rhs.m_iCol;
}

bool	Point::operator!=(const	Point&	rhs){
return	!operator==(rhs);
}

bool	Point::operator==(const	Point&	rhs){
return	(m_iRow==	rhs.m_iRow)&&(m_iCol== rhs.m_iCol);
}

Point&	Point::operator= (const	Point&	rhs){
m_iRow		=	rhs.m_iRow;
m_iCol		=	rhs.m_iCol;
return	*this;
}
//=========================================================================
//end of class	Point	define
//=========================================================================

//=========================================================================
//begin class	CState	define
//=========================================================================
class CState{			//存储9宫的状态
public:
CState(const	CState&	rhs);
CState();

public:
CState&	operator=(const	CState&	rhs);
bool	operator==(const	CState&	rhs);

public:
int		vValue[3][3];
Point	m_Center;	//我们设0的位置是Center
};

CState::CState(const CState& rhs):m_Center(rhs.m_Center){
for(int iRow= 0; iRow< 3; ++iRow){
for(int iCol= 0; iCol< 3; ++iCol)
vValue[iRow][iCol]	=	rhs.vValue[iRow][iCol];
}
}

CState::CState(){}

CState&	CState::operator= (const	CState&	rhs){
m_Center		=	rhs.m_Center;
for(int iRow= 0; iRow< 3; ++iRow){
for(int iCol= 0; iCol< 3; ++iCol)
vValue[iRow][iCol]	=	rhs.vValue[iRow][iCol];
}
return	*this;
}

bool	CState::operator==(const	CState&	rhs){
if(m_Center !=	rhs.m_Center)
return	false;
for(int iRow= 0; iRow< 3; ++iRow){
for(int iCol= 0; iCol< 3; ++iCol)
if(vValue[iRow][iCol]	!=	rhs.vValue[iRow][iCol])
return	false;
}
return	true;
}
//=========================================================================
//end of class	CState	define
//=========================================================================

CState		StateBegin, StateEnd;	//开始和结束状态
int			Search();
int			StateToInt(const	CState&	state);//编码
CState		IntToState(int		iState);	   //解码

int	main(){
for(int	iRow=	0; iRow< 3; ++iRow){
for(int	iCol= 0; iCol< 3; ++iCol){
cin>>StateBegin.vValue[iRow][iCol];
if(StateBegin.vValue[iRow][iCol]== 0){
StateBegin.m_Center.m_iRow=	iRow;
StateBegin.m_Center.m_iCol=	iCol;
}
}
}

for(int	iRow=	0; iRow< 3; ++iRow){
for(int	iCol= 0; iCol< 3; ++iCol){
cin>>StateEnd.vValue[iRow][iCol];
if(StateEnd.vValue[iRow][iCol]== 0){
StateEnd.m_Center.m_iRow=	iRow;
StateEnd.m_Center.m_iCol=	iCol;
}
}
}
cout<<Search()<<endl;
}

int			StateToInt(const	CState&	state){//编码
int		iValue	=	0;
for(int	iRow=	2; iRow>= 0; --iRow){
for(int	iCol=2; iCol>= 0; --iCol){
iValue*= 9;
iValue+= state.vValue[iRow][iCol];
}
}
return	iValue;
}

CState		IntToState(int		iState){	   //解码
CState	state;
for(int	iRow= 0; iRow< 3; ++iRow){
for(int	iCol= 0; iCol< 3; ++iCol){
state.vValue[iRow][iCol]	=	iState%9;
iState/= 9;
if(state.vValue[iRow][iCol]== 0){
state.m_Center.m_iRow	=	iRow;
state.m_Center.m_iCol	=	iCol;
}
}
}
return	state;
}

//=========================================================================
//BFS search
//=========================================================================
int			Search(){
list<CState>	buffer1, buffer2;
int				iStep= 0;
list<CState>	*lpListUsed;		//存放当前这一步
list<CState>	*lpListNextStep;	//存放下一步
if(StateBegin==	StateEnd)
return	0;			//直接到达的话就是0了
lpListUsed			=	&buffer1;
lpListNextStep		=	&buffer2;
lpListUsed->push_back(StateBegin);
int		iPosition	=	StateToInt(StateBegin);
bVisitTag[iPosition]		=	true;
//bVisitTag[StateToInt(StateBegin)]=	true;	//打标记
while(!lpListUsed->empty()){
CState	StateNow;
CState	StateNext;
++iStep;
while(!lpListUsed->empty()){
StateNow=	lpListUsed->front();
lpListUsed->pop_front();
if(StateNow==	StateEnd){
return	iStep-1;
}
if(StateNow.m_Center.m_iRow-1>= 0){
StateNext	=	StateNow;
--StateNext.m_Center.m_iRow;
StateNext.vValue[StateNow.m_Center.m_iRow][StateNow.m_Center.m_iCol]	=StateNow.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol];
StateNext.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol]	=	0;
int	iPosition	=	StateToInt(StateNext);
if(!bVisitTag[iPosition]){
bVisitTag[iPosition]=	true;
lpListNextStep->push_back(StateNext);
}
}
if(StateNow.m_Center.m_iRow+1< 3){
StateNext	=	StateNow;
++StateNext.m_Center.m_iRow;
StateNext.vValue[StateNow.m_Center.m_iRow][StateNow.m_Center.m_iCol]	=StateNow.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol];
StateNext.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol]	=	0;
int	iPosition	=	StateToInt(StateNext);
if(!bVisitTag[iPosition]){
bVisitTag[iPosition]=	true;
lpListNextStep->push_back(StateNext);
}
}
if(StateNow.m_Center.m_iCol-1>= 0){
StateNext	=	StateNow;
--StateNext.m_Center.m_iCol;
StateNext.vValue[StateNow.m_Center.m_iRow][StateNow.m_Center.m_iCol]	=StateNow.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol];
StateNext.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol]	=	0;
int	iPosition	=	StateToInt(StateNext);
if(!bVisitTag[iPosition]){
bVisitTag[iPosition]=	true;
lpListNextStep->push_back(StateNext);
}
}
if(StateNow.m_Center.m_iCol+1< 3){
StateNext	=	StateNow;
++StateNext.m_Center.m_iCol;
StateNext.vValue[StateNow.m_Center.m_iRow][StateNow.m_Center.m_iCol]	=StateNow.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol];
StateNext.vValue[StateNext.m_Center.m_iRow][StateNext.m_Center.m_iCol]	=	0;
int	iPosition	=	StateToInt(StateNext);
if(!bVisitTag[iPosition]){
bVisitTag[iPosition]=	true;
lpListNextStep->push_back(StateNext);
}
}
}
std::swap(lpListUsed, lpListNextStep);
}
return	-1;
}