#include "StdAfx.h"
#include ".\sudoku.h"

#include <exception>

//bruges til debug prints
#define LINE "+---+---+---+---+---+---+---+---+---+\r\n"


Sudoku::Sudoku(void)
{
	clear();
}

Sudoku::~Sudoku(void)
{
}


CString Sudoku::print_matrix() 
{
	CString out;

	int i,j,tal;
	for(i=0; i<matrixSize; i++) {
		out += LINE ;
		for (j=0; j<matrixSize; j++) {
			tal = matrix[j][i];
			if (tal != 0) {
				out.AppendFormat("| %d ", tal);
			}
			else
				out += "|   ";
		}
		out += "|\r\n";
	}
	out += LINE ;
	return out;
}

void Sudoku::clear() 
{
	for (int i=0; i<matrixSize; i++)
		for (int j=0; j<matrixSize; j++) {
			user_matrix[i][j] = false;
			matrix[i][j] = 0;
		}
}

void Sudoku::clearCalculated(void)
{
	for (int i=0; i<matrixSize; i++)
		for (int j=0; j<matrixSize; j++) {
			if (user_matrix[i][j] == false)
				matrix[i][j] = 0;
		}
}


bool Sudoku::checkrow(int x, int y, int tal) 
{
	for (int i=0; i<matrixSize; i++) {
		if (matrix[x][i] == tal)
			return true;
	}
	return false;
}


bool Sudoku::checkcol(int x, int y, int tal) 
{
	int i;
	for (i=0; i<matrixSize; i++) {
		if (matrix[i][y] == tal)
			return true;
	}
	return false;
}

bool Sudoku::checkbox(int x, int y, int tal) 
{
	int startx,starty;
	startx = x - (x%3);
	starty = y - (y%3);

	for (int row=startx; row<(startx+3); row++)
		for (int col=starty; col<(starty+3); col++)
			if (matrix[row][col] == tal)
				return true;

	return false;
}

bool Sudoku::solve(int x, int y) 
{
	int tal;
	bool res;

	if (y >= matrixSize)
		return true;

	if (x >= matrixSize) {
		x=0;
		y++;
	}

	while (user_matrix[x][y] == true) {
		x++;
		if (x>=matrixSize) {
			x=0;
			y++;
		}
	}

	if (y>=matrixSize)
		return true; //out of range

	for (tal=1; tal<=matrixSize; tal++) {
		if ( checkrow(x,y,tal) || checkcol(x,y,tal) || checkbox(x,y,tal) )
			continue;

		matrix[x][y] = tal;
		res = solve(x+1,y);

		if (res == true)
			return res;
	}
	matrix[x][y] = 0; //before stepping back, clear the current field
	return false;
}

bool Sudoku::solve() 
{
	clearCalculated();
	initCheck();
	return solve(0,0);
}


void Sudoku::setNumber(int x, int y, int number)
{
	matrix[x][y] = number;
	if (number != 0)
		user_matrix[x][y] = true;
	else
		user_matrix[x][y] = false;

}

int Sudoku::getNumber(int x, int y)
{
	return matrix[x][y];
}

bool Sudoku::getUser(int x, int y)
{
	return user_matrix[x][y];
}


// laver en check på om det bruger-indtastede problem kan løses eller om dataene har en intern konflikt
void Sudoku::initCheck(void)
{
	int tal;
	bool res;

	for (int i=0; i<matrixSize; i++) {
		for (int j=0; j<matrixSize; j++) {
			if (matrix[i][j] != 0) {
				tal = matrix[i][j];
				matrix[i][j] = 0;
				res= (checkrow(i,j,tal) || checkcol(i,j,tal) || checkbox(i,j,tal));
				matrix[i][j] = tal;
				if (res)
					throw std::exception("Invalid user matrix");
			}
		}
	}
}