/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_ten_queens_puzzle.c                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: tosuman </var/spool/mail/tosuman>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/03/30 17:05:04 by tosuman           #+#    #+#             */
/*   Updated: 2023/03/30 17:05:06 by tosuman          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include <unistd.h>
#include <stdio.h>
#define SIZE 10

void	ft_putchar(char c)
{
	write(1, &c, 1);
}

// print the current board and return sols+1
int	new_sol(int cols[SIZE], int sols)
{
	int	i;

	i = -1;
	while (++i < SIZE)
		ft_putchar(cols[i] + '0');
	ft_putchar('\n');
	return (sols + 1);
}

int	is_valid_board(int cols[SIZE], int col)
{
	int	i;

	i = col;
	while (--i >= 0)
		if (cols[i] == cols[col])
			return (0);
	i = 0;
	while (++i <= cols[col])
		if (cols[col - i] == cols[col] - i && i <= col)
			return (0);
	i = 0;
	while (++i < SIZE - cols[col] && i <= col)
	{
		if (cols[col - i] == cols[col] + i)
			return (0);
	}
	return (1);
}

int	backtrack(int cols[SIZE], int col, int sols)
{
	int	i;

	if (col >= SIZE)
	{
		return (new_sol(cols, sols));
	}
	i = -1;
	while (++i < SIZE)
	{
		cols[col] = i;
		if (is_valid_board(cols, col))
			sols += backtrack(cols, col + 1, 0);
		cols[col] = -1;
	}
	return (sols);
}

int	ft_ten_queens_puzzle(void)
{
	int	cols[SIZE];
	int	i;

	i = -1;
	while (++i < SIZE)
		cols[i] = -1;
	return (backtrack(cols, 0, 0));
}

/* ////
#include <stdio.h>

int	main(void)
{
	printf("%d\n", ft_ten_queens_puzzle());
	return (0);
}
*/ ////