数独程序

//by Arthur

//2011.5

#include<stdio.h>

#include<stdlib.h>

//将大九宫格分成小九宫格

#define CASE1 3

#define CASE2 6

#define CASE3 9

typedef struct cell{

  int key;

  int state;

}cell; //数独节点,key->填入值,state->数独节点当前状态

int goon=1;//递归方向控制

void shudu(cell (*array)[9],int start);//数独函数，输入参数:由数独节点组成的二维数组；遍历起始点

int main()

{

  cell array[9][9];

  int i,j;

  int temp;

  printf("input shudu:\n");

  //输入数独，无值处填0

  for(i=0;i<9;i++)

    for(j=0;j<9;j++)

    {

      scanf("%d",&temp);

      array[i][j].key=temp;

      if(temp==0)

        array[i][j].state=0; //可变更节点

      else

        array[i][j].state=1; //不可变更节点

    }

    

    shudu(array,0);//遍历起始点->0

    

    //打印结果

    for(i=0;i<9;i++)

      for(j=0;j<9;j++)

      {

        printf("%d",array[i][j].key);

        if(j==8) 

          printf("\n");

        else

          printf(" ");

 

      }

  

 

  return EXIT_SUCCESS;//成功退出

 

}

void shudu(cell (*array)[9],int start)

{

   if(start==81)//回溯终止条件

   {

     printf("got it \n");

     return;

   }

   

   //将节点序号变换为对应的行列值

   int row=start/9;

   int column=start%9;

   

   if(array[row][column].state==1)//不可变更状态

   {

     if(goon==1)//遍历下一个节点

     {

       shudu(array,++start);

     }   

     else

     {

       if(start==0)//无结果

       {

         return;

       }

       else//回溯

       {

         shudu(array,--start);

       }

     }

 

   }

   else//可变更节点

   {

     int i;

       

 

     for(i=array[row][column].key+1;i<10;i++)//测试可用值

     {

     

       int state1=1,state2=1,state3=1;

         

       int p,q;

    

       for(p=0;p<9;p++)

       {

         if((array[p][column].key==i)&&(p!=row))//检验行冲突

         {

           state1=0;

           break;

         }

         if((array[row][p].key==i)&&(p!=column))//检验列冲突

         {

           state2=0;

           break;

         }

       }

       

       int row_l,column_l;

       //确定所在小方块

       if(row<CASE1)

       {

         row_l=CASE1;

       }

       else if(row<CASE2)

       {

         row_l=CASE2;

       }

       else

       {

         row_l=CASE3;

       }

       

       if(column<CASE1)

       {

         column_l=CASE1;

       }

       else if(column<CASE2)

       {

         column_l=CASE2;

       }

       else

       {

         column_l=CASE3;

       }

       //检验小方块内冲突

       for(p=row_l-3;p<row_l;p++)

         for(q=column_l-3;q<column_l;q++)

         {

           if((array[p][q].key==i)&&!(p==row&&q==column))

           {

             state3=0;

             p=row_l;

             q=column_l;

 

           }

           

         }

        

       if((state1==1)&&(state2==1)&&(state3==1))//无冲突

       {

         break;

       }

 

 

     }

     

     if(i==10)//当前节点无可用值，回溯

     {

       array[row][column].key=0;

       goon=-1;

       shudu(array,--start);

     

     }

     else//当前节点存在可用值，遍历下一个节点

     {

       array[row][column].key=i;

       goon=1;

       shudu(array,++start);

 

     }

 

  

 

   }

  

 

}