aoc1503_deliver.cpp

/* ************************************************************************** */
/*                                                                            */
/*                            \\             /`/``                            */
/*                            ~\o o_       0 0\                               */
/*                            / \__)      (u  ); _  _                         */
/*                     / \/ \/  /           \  \/ \/ \                        */
/*                    /(   . . )            (         )\                      */
/*                   /  \_____/              \_______/  \                     */
/*                       []  []               [[] [[]    *.                   */
/*                       []] []]              [[] [[]                         */
/*                                                                            */
/* ****************************************************************** nxu *** */

#include "iostream"
#include "vector"
#include "utility"	// pair . make_pair

int	if_exists(std::pair<int, int> pair, std::vector< std::pair<int, int> > path);

int	main()
{
	std::vector<std::pair<int, int> > path_santa;
	std::vector<std::pair<int, int> > path_claus;
	int			step, x, y, a, b, c, d;
	char			buff;

	step = x = y = 0;
	a = b = 0;
	c = d = 0;
	path_santa.push_back(std::make_pair(x, y));
	path_claus.push_back(std::make_pair(x, y));
	while (std::cin >> buff)
	{
		if (buff == '>')
		{
			x++;
			if (step % 2)
				a++;
			else
				c++;
		}
		if (buff == '<')
		{
			x--;
			if (step % 2)
				a--;
			else
				c--;
		}
		if (buff == '^')
		{
			y++;
			if (step % 2)
				b++;
			else
				d++;
		}
		if (buff == 'v')
		{
			y--;
			if (step % 2)
				b--;
			else
				d--;
		}
		std::pair<int, int>	pos_santa = std::make_pair(x, y);
		std::pair<int, int>	pos_nick = std::make_pair(a, b);
		std::pair<int, int>	pos_robo = std::make_pair(c, d);
		if (!if_exists(pos_santa, path_santa))
			path_santa.push_back(pos_santa);
		if (!if_exists(pos_nick, path_claus))
			path_claus.push_back(pos_nick);
		if (!if_exists(pos_robo, path_claus))
			path_claus.push_back(pos_robo);
		step++;
	}
	std::cout 
	<< "Star 1: " << path_santa.size() << '\n'
	<< "Star 2: " << path_claus.size() << '\n';
}

//

int     if_exists(std::pair<int, int> pair, std::vector< std::pair<int, int> > path)
{
	int	mark, i;

	i = -1;
	mark = 0;
	while (++i < (int) path.size())
	{
		if (pair == path[i])
			mark++;
	}
	return (mark);
}