#include<cvc\matrix.h>
#include<iostream.h>
#include<cvc\random.h>
#include<cvc\xconio.h>


int checknum(const matrix<char> answer, int row, int col, int num)
{// return 1 if the randomized number can not be placed in the block

	//row
	int number=0;
	char letter;
	int limit=0,limit2=0;
	for(int column=0;column<answer.numcols();column++){
		letter=answer[row][column];
		number = int(letter)-48;
		if(number==num)
			return(1);
	}
	//column
	for(int Rows=0;Rows<answer.numrows();Rows++){
		letter=answer[Rows][col];
		number=int(letter)-48;
		if(number==num)
			return(1);
	}
	//Block
	//determining which block
	Rows = (row/3);
	Rows = (Rows+(2 * Rows));
	limit=(Rows+3);

	column = (col/3);
	column = (column+(2 * column));
	limit2=(column+3);

	//checking it
	for(Rows;Rows<limit;Rows++){
		for(column;column<limit2;column++){
			letter =answer[Rows][column];
			number =int(letter)-48;
			if(number==num)
				return(1);
		}
	}

	return(-1);
}

//------------------------------------------------------------------


int boardfull(const matrix<char> answer)
// returns 1 if not full, -1 if full
{
	for(int row=0;row<answer.numrows();row++){
		for(int col=0;col<answer.numcols();col++){
			if(answer[row][col]==' ')
				return(1);
		}
	}
	return(-1);
}


//----------------------------------------------------------------

void displayboard(const matrix<char> &sudoku)
{
	cout<<"  ";
	for(int i=1; i<=9; i++)
		cout<<i<<" ";
	cout<<endl;
	cout<<"  ";
	for(int b=1;b<=9;b++)
		cout<<"- ";
	cout<<endl;

	for(int row=0;row<sudoku.numrows(); row++){
		cout<<(row+1)<<"|";
		for(int cols=0;cols<sudoku.numcols();cols++)
			cout<<sudoku[row][cols]<<" ";
		cout<<"|";
		cout<<endl;
	}

	cout<<"  ";
	for(int w = 1; w<=9; w++)
			cout<<"- ";
	cout<<endl;

}

//----------------------------------------------------------------

int checkanswer(const matrix<char> &answer,const matrix<char> &user)
{
	for(int row=0;row<answer.numrows();row++){
		for(int col=0;col<answer.numcols();col++){
			if(answer[row][col] != user[row][col])
				return(-1);
		}
	}

	return(1);
}


//----------------------------------------------------------------

int main()
{
	randomize();
	matrix<char> answer(9,9,' ');
	int row,col,num;
	long stop=0;//check infinite variable
	int	quit=0;//quits and tries again variable

	matrix<char> def(9,9,' ');


	do{
		answer=def;
		quit=0;
			for(row=0;row<answer.numrows();row++){
				stop=0;
					for(col=0;col<answer.numcols();col++){
						do{
							num=random(9)+1;
							stop++;
							if(stop>30){
								quit=1;
								break;
							}
						}while(checknum(answer,row,col,num)==1);
						if(quit==0){
							answer[row][col]=char(num+48);
							stop=0;}
						else
							break;
					}
				if(quit==1)
					break;
			}

	}while(boardfull(answer)==1);

	clrscr();
		for(int r=0;r<9;r++){
			for(int c=0;c<9;c++)
				cout<<answer[r][c]<<" ";
		cout<<endl;
		}

	getche();
	clrscr();


	char ans;
	matrix<char> user(9,9,' ');
	int defnum=0;

	do{
		cout<<"Choose difficulty:Easy,Medium,Hard ";
		cin>>ans;
		if(ans =='e' || ans == 'E'){
			defnum=40;
			break;}
		else if(ans=='m'||ans=='M'){
			defnum=35;
			break;}
		else if(ans=='h'||ans=='H'){
			defnum=30;
			break;}
	}
	while(true);


	clrscr();

	for(int give=1;give<=defnum;give++){
		row = random(9);
		col = random(9);
		if(def[row][col]==' ')
			def[row][col]=answer[row][col];
		else
			give--;
	}



	user=def;

	do{
		clrscr();
		displayboard(user);
		gotoxy(0,20);
		row = 0;
		col=0;
		cout<<"Choose what you want to do:Put or Remove";
		cin>>ans;
		if(ans=='P'||ans=='p'){
			cout<<"what row would you like?";
			cin>>row;
			row = row-1;
			cout<<"what column would you like?";
			cin>>col;
			col = col-1;
			cout<<"what number is being put here?";
			cin>>num;
				if(user[row][col] == ' ')
					user[row][col]=char(num+48);
				else
					cout<<"sorry cant put it here";
		}

		if(ans=='r' || ans=='R'){
			cout<<"what row would you like?";
			cin>>row;
			row = row-1;
			cout<<"what column would you like?";
			cin>>col;
			col = col-1;
				if(def[row][col] ==' ')
					user[row][col]=' ';
				else
					cout<<"You cant remove this number, its here by default";

		}

		cout<<endl;

		getche();





	}while(checkanswer(answer,user)==-1);

	cout<<"Congrats, you the man!";




	return(0);
}