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Need Help WIth my Sudoku Code

killerelite (3)
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#include<iostream>
using namespace std;
int sudoku[9][9] = { {0} };
int checker[81][2];
int check = 0;
void solvesudoku(int, int);
bool checkrow(int row, int num)
{
	for (int column = 0; column < 9; column++)
		if (sudoku[row][column] == num)
			return false;
	return true;
}
bool checkcolumn(int column, int num)
{
	for (int row = 0; row < 9; row++)
		if (sudoku[row][column] == num)
			return false;
	return true;
}
bool checkgrid(int row, int column, int num)
{
	row = (row / 3) * 3;
	column = (column / 3) * 3;
	int r, c;
	for (r = 0; r < 3; r++)
		for (c = 0; c < 3; c++)
			if (sudoku[row + r][column + c] == num)
				return false;
	return true;
}
void navigate(int &row, int &column)
{
	if (column < 8)
		column++;
	else
	{
		column = 0;
		row++;
	}
}
void display()
{
	int row, column;
	cout << "Soloution=" << endl;
	for (row = 0; row<9; row++)
	{
		for (column = 0; column < 9; column++)
		{
			cout << sudoku[row][column];
			if ((column + 1) % 3 == 0)
				cout << "  ";
		}
		cout << endl;
		if ((row + 1) % 3 == 0)
			cout << endl;
	}
	system("pause");
}
void navigatebackward()
{
	check--;
	int row = checker[check][0];
	int column = checker[check][1];
	for (int safe = sudoku[row][column]+1; safe <= 9; safe++)
	{
		if (checkrow(row, safe) == true && checkcolumn(column, safe) == true && checkgrid(row, column, safe) == true)
		{
			sudoku[row][column] = safe;
			check++;
			break;
		}
		else
		{
			sudoku[row][column] = 0;
		}
	}
	if (sudoku[row][column] == 0)
		navigatebackward();
	navigate(row,column);


}
void solvesudoku(int row = 0, int column = 0)
{
	while (row < 8)
	{
		if (sudoku[row][column] != 0)
			navigate(row, column);
		else
		{
			checker[check][0] = row;
			checker[check][1] = column;
			for (int safe = 1; safe <= 9; safe++)
			{
				if (checkrow(row, safe) == true && checkcolumn(column, safe) == true && checkgrid(row, column, safe) == true)
				{
					sudoku[row][column] = safe;
					check++;
					display();
					break;
				}
			}
			if (sudoku[row][column] == 0)
			{
				navigatebackward();
			}
		}
	}
}
void main()
{
	solvesudoku();
	display();
}
Last edited on
TheIdeasMan (6817)
Write your question here.


You didn't ask a question.

Need Help WIth my Sudoku Code


What help? Be specific about what the problem is, what goes wrong for you?

111:11: error: '::main' must return 'int'


I guess you are using TurboC++V3.0, and you are in India ? If so, be aware this compiler is ancient, and will be seriously down on features - even namespace std.

If not, as the error says main returns an int, it's mandated in the C++ standard.

If the code compiles, consider using a debugger to see where it goes wrong.

Just an observation this doesn't look any where near enough code to solve sudoku, do you have 9 numbers for each of the 81 squares, to serve as the candidates for each square? Where are you allowing for locked pairs and locked triples?

Hope this helps a little :+)



http://www.sudoku-help.com/Worked-Example.htm
Last edited on
killerelite (3)
I am using Visual studio 2015.
Whats wrong is that it isnt solving the sudoku fully .
killerelite (3)
int sudoku[9][9] Initilizes the sudoku
checker[81][2] is used to go back to the previous filled box incase no number from 1-9 can be filled in the box
TheIdeasMan (6817)
Whats wrong is that it isnt solving the sudoku fully .


Have a look at the link I posted :+)
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