Hi Guys !!
I'm new to this forum so please excuse me if i'm not posting my problem correctly.
I have been given a project to make a program in C++ that solves a given sudoku problem.
Here is what i did :
#include<iostream.h>
#include<conio.h>
int board[9][9];
int checkrow(int t, int _x, int _y)
{
int c=1;
for(int y=0; y<9 && c==1 ; y++)
if(board[_x][y]==t)
c=0;
return c;
}
int checkcol(int t, int _x, int _y)
{
int c=1;
for(int x=0; x<9 && c==1 ; x++)
if(board[x][_y]==t)
c=0;
return c;
}
int checkbox(int t, int _x, int _y)
{
int c=1;
int __x=(_x+1)%3, __y=(_y+1)%3;
switch(__x)
{
case 0: switch(__y)
{
case 0:{
for(int x=_x ; x>=_x-2 && c==1 ; x--)
for(int y=_y ; y>=_y-2 && c==1; y--)
if(board[x][y]==t)
c=0;
}
break;
case 1:{
for(int x=_x ; x>=_x-2 && c==1 ; x--)
for(int y=_y ; y<=_y+2 && c==1; y++)
if(board[x][y]==t)
c=0;
}
break;
case 2:{
for(int x=_x ; x>=_x-2 && c==1 ; x--)
for(int y=_y-1 ; y<=_y+2 && c==1; y++)
if(board[x][y]==t)
c=0;
}
break;
}
break;
case 1: switch(__y)
{
case 0:{
for(int x=_x ; x<=_x+2 && c==1 ; x++)
for(int y=_y ; y>=_y-2 && c==1; y--)
if(board[x][y]==t)
c=0;
}
break;
case 1:{
for(int x=_x ; x<=_x+2 && c==1 ; x++)
for(int y=_y ; y<=_y+2 && c==1; y++)
if(board[x][y]==t)
c=0;
}
break;
case 2:{
for(int x=_x ; x<=_x+2 && c==1 ; x++)
for(int y=_y-1 ; y<=_y+2 && c==1; y++)
if(board[x][y]==t)
c=0;
}
break;
}
break;
case 2: switch(__y)
{
case 0:{
for(int x=_x-1 ; x<=_x+2 && c==1 ; x++)
for(int y=_y ; y>=_y-2 && c==1; y--)
if(board[x][y]==t)
c=0;
}
break;
case 1:{
for(int x=_x-1 ; x<=_x+2 && c==1 ; x++)
for(int y=_y ; y<=_y+2 && c==1; y++)
if(board[x][y]==t)
c=0;
}
break;
case 2:{
for(int x=_x-1 ; x<=_x+2 && c==1 ; x++)
for(int y=_y-1 ; y<=_y+2 && c==1; y++)
if(board[x][y]==t)
c=0;
}
break;
}
break;
}
return c;
}
struct node
{
int x, y;
node* next;
};
class list
{
node* top;
public:
list(){top=NULL;}
node* rettop(){return top;}
void add(int , int);
};
void list::add(int x, int y)
{
if(!top)
{
top=new node;
top->x=x;
top->y=y;
top->next=NULL;
}
else
{
node* ptr=new node;
ptr->x=x;
ptr->y=y;
ptr->next=top;
top=ptr;
}
}
void solve(node* point)
{
if(point)
{
for(int t=1; t<10; t++)
{
if(checkrow(t, point->x, point->y))
if(checkcol(t, point->x, point->y))
if(checkbox(t, point->x, point->y))
{
board[point->x][point->y]=t;
solve(point->next);
if(point->next)
{
if(board[point->next->x][point->next->y]==0)
board[point->x][point->y]=0;
else
break;
}
else
break;
}
}
}
}
void main()
{
list a;
for(int x=0; x<9; x++)
cin>>board[x][0]>>board[x][1]>>board[x][2]
>>board[x][3]>>board[x][4]>>board[x][5]
>>board[x][6]>>board[x][7]>>board[x][8];
for(int x=8; x>=0; x--)
for(int y=8; y>=0; y--)
if(board[x][y]==0)
a.add(x, y);
solve(a.rettop());
for(int x=0; x<9; x++)
cout<<board[x][0]<<board[x][1]<<board[x][2]
<<board[x][3]<<board[x][4]<<board[x][5]
<<board[x][6]<<board[x][7]<<board[x][8]<<endl;
getch();
}Whenever I run the program , It gives back the original puzzle to me.
But what was interesting was that suppose u gave it a completely blank puzzle or a puzzle with 5-6 blanks then it came up with the correct solution.
I know I'm making some very careless error somewhere.
Please tell me if I'm doing something wrong.
NOTE: The program takes 0 for blanks and the input has to be row wise with the numbers seperated by spaces.
Thanks in advance
