From 1524457a5b2666d6211557645dd056c2d1585a6e Mon Sep 17 00:00:00 2001
From: =?utf8?q?Luk=C3=A1=C5=A1=20Ji=C5=99i=C5=A1t=C4=9B?=
 <gymnazium.jiriste@gmail.com>
Date: Wed, 6 Dec 2023 10:04:07 +0100
Subject: [PATCH] Add solution to first part of day 6.

---
 6/6.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 6/6.c

diff --git a/6/6.c b/6/6.c
new file mode 100644
index 0000000..e626761
--- /dev/null
+++ b/6/6.c
@@ -0,0 +1,77 @@
+
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <math.h>
+#include "libft.h"
+
+int	special_is_whole(int time, int record)
+{
+	int	n;
+
+	n = 1;
+	while (n <= time / 2)
+	{
+		if (record == n * (time - n))
+			return (1);
+		++n;
+	}
+	return (0);
+}
+
+int	ways_of_winning(int time, int record)
+{
+	double	special;
+	int		correction;
+
+	correction = 0;
+	special = sqrt(time * time / 4. - record);
+	if (isnan(special))
+		return (0);
+	if (special_is_whole(time, record))
+	{
+		if (special < 1)
+			return (0);
+		correction = 2;
+	}
+	if (time % 2 == 0)
+		return (2 * floor(special) + 1 - correction);
+	if (fmod(special, 1.) < 0.5)
+		return (2 * floor(special) - correction);
+	return (2 * floor(special) + 2 - correction);
+}
+
+int	main(int argc, char **argv)
+{
+	int		fd;
+	int		result;
+	char	*times;
+	char	*records;
+	size_t	t;
+	size_t	r;
+
+	fd = open(argv[1], O_RDONLY);
+	times = get_next_line(fd);
+	records = get_next_line(fd);
+	t = 0;
+	r = 0;
+	result = 1;
+	while (times[t] != '\n' && records[r] != '\n')
+	{
+		while (!ft_isdigit(times[t]))
+			++t;
+		while (!ft_isdigit(records[r]))
+			++r;
+		result *= ways_of_winning(ft_atoi(times + t), ft_atoi(records + r));
+		while (ft_isdigit(times[t]))
+			++t;
+		while (ft_isdigit(records[r]))
+			++r;
+	}
+	ft_printf("The resulting product is %i.\n", result);
+	get_next_line(fd);
+	close(fd);
+	free(times);
+	free(records);
+	return (0);
+}
-- 
2.30.2