N皇后问题

//queen.h

class Queen

{

private:

         int number;//皇后数

         bool *row;//行是否有随机数

         bool *diag;//主对角线是否有皇后数

         bool *backDiag;//反对角线是否有皇后数

         int *x;//解

         static int num;//解得个数

 

         //辅助函数

 

         void BackTracking(int c);//回溯法递归求解

         void Show();//显示解

public:

         Queen();

         virtual ~Queen();

         void Run();

};

int Queen::num=0;

Queen::Queen()

{

         cout<<"请输入皇后数:"<<endl;

         cin>>number;

         row=new bool[number+1];

         diag=new bool[2*number];

         backDiag=new bool[2*number];

         x=new int[number+1];

 

         int i;

         for(i=1;i<=number;i++)

                   row[i]=false;

         for(i=1;i<2*number;i++)

                   diag[i]=false;

         for(i=1;i<2*number;i++)

                   backDiag[i]=false;

 

 

}

Queen::~Queen()

{

         delete []row;

         delete []diag;

         delete []backDiag;

         delete []x;

}

void Queen::Run()

{

         BackTracking(1);

}

void Queen::Show()

{

         cout<<"第"<<++num<<"个解";

         cout<<"("<<x[1];

         for(int i=2;i<=number;i++)

                   cout<<","<<x[i];

         cout<<")"<<endl;

}

void Queen::BackTracking(int c)

{

         if(c>number)

                   Show();

         else

         {

                   for(int r=1;r<=number;r++)

                   {

                            if(!row[r]&&!diag[number-c+r]&&!backDiag[r+c-1])

                            {

                                     row[r]=diag[number-c+r]=backDiag[r+c-1]=true;

                                     x[c]=r;

                                     BackTracking(c+1);

                                     row[r]=diag[number-c+r]=backDiag[r+c-1]=false;

                            }

                   }

 

         }

}

 

//main.cpp

 

#include "utility.h"

#include"queen.h"

void main()

{

         system("color 24");

         Timer obj;

         Queen objQueen;

         objQueen.Run();

         cout<<"用时"<<obj.ElapsedTime()<<"秒"<<endl;

         system("pause");

}