add day 9 (a bit slow)

2025/9/part2.c

@@ -0,0 +1,166 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   part2.c                                            :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tomoron <tomoron@student.42.fr>            +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/07/17 23:03:36 by tomoron           #+#    #+#             */
+/*   Updated: 2025/12/10 15:08:17 by tomoron          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include "libft/libft.h"
+
+typedef struct s_cords
+{
+	double x;
+	double y;
+}	t_coords;
+
+static t_coords parse_line(char *line)
+{
+	t_coords res;
+
+	res.x = atoi(line);
+	while(ft_isdigit(*line))
+		line++;
+	line++;
+	res.y = atoi(line);
+	return(res);
+}
+
+static int is_point_on_line(t_coords pos, t_coords a, t_coords b)
+{
+	double cross = (pos.x - a.x) * (b.y - a.y) - (pos.y - a.y) * (b.x - a.x);
+	if(cross != 0)
+		return(0);
+	return(pos.x >= fmin(a.x, b.x) && pos.x <= fmax(a.x, b.x) &&
+			pos.y >= fmin(a.y, b.y) && pos.y <= fmax(a.y, b.y));
+
+}
+
+
+static int is_point_in_poly(t_coords pos, t_coords *poly, int len)
+{
+	int inside;
+	int i;
+	t_coords cur[2];
+	double intersect;
+
+	inside = 0;
+	i = 0;
+	while(i < len)
+	{
+		cur[0] = poly[i];	
+		cur[1] = poly[(i + 1) % len];
+
+		if(is_point_on_line(pos, cur[0], cur[1]))
+		{
+			inside = 1;
+			break;
+		}
+
+		if((cur[0].y > pos.y) != (cur[1].y > pos.y))
+		{
+			intersect = ((cur[1].x - cur[0].x) *  (pos.y - cur[0].y)) / (cur[1].y - cur[0].y) + cur[0].x;
+			if(pos.x < intersect)
+				inside = !inside;
+		}
+		i++;
+	}
+	return(inside);
+}
+
+static int is_line_in_poly(t_coords p1, t_coords p2, t_coords *poly, int len)
+{
+	t_coords from;
+	t_coords to;
+
+	from.x = fmin(p1.x, p2.x);
+	from.y = fmin(p1.y, p2.y);
+	to.x = fmax(p1.x, p2.x);
+	to.y = fmax(p1.y, p2.y);
+
+	while(from.x <= to.x && from.y <= to.y)
+	{
+		if(!is_point_in_poly(from, poly, len))
+		{
+			return(0);
+		}
+		if(from.x != to.x)		
+			from.x++;
+		else
+			from.y++;
+	}
+	return(1);
+}
+
+static int is_all_in_poly(t_coords p1, t_coords p2, t_coords *poly, int len)
+{
+
+	if(!is_line_in_poly(p1,(t_coords){p2.x, p1.y}, poly, len) || 
+		!is_line_in_poly((t_coords){p2.x, p1.y}, p2, poly, len) || 
+		!is_line_in_poly(p2, (t_coords){p1.x, p2.y}, poly, len) || 
+		!is_line_in_poly((t_coords){p1.x, p2.y},p1, poly, len))
+		return(0);
+	return(1);
+}
+
+static long int get_biggest_area(t_coords *co, int len)
+{
+	int i;
+	int j;
+	long int max;
+	long int tmp;
+
+	i = 0;
+	max = 0;
+	while(i < len)
+	{
+		j = i;
+		while(++j < len)
+		{
+			if(i == j)
+				continue;
+			tmp = ((long)fabs(co[i].x - co[j].x) + 1) * ((long)fabs(co[i].y - co[j].y) + 1);
+			if(tmp <= max)
+				continue;
+			if(!is_point_in_poly((t_coords){co[i].x,co[j].y}, co, len) || !is_point_in_poly((t_coords){co[j].x,co[i].y}, co, len))
+				continue;
+			if(!is_all_in_poly(co[i], co[j], co, len))
+				continue;
+			printf("got %ld for %.0f, %.0f to %.0f, %.0f checking points \n", tmp, co[i].x, co[i].y, co[j].x, co[j].y);
+			max = tmp;
+		}
+		i++;
+	}
+	return(max);
+}
+
+long int resolve_part2(char *input, char **split)
+{
+	(void)input;
+	int len;
+	t_coords *co;
+	int i;
+
+	len = 0;
+	while(split[len])
+		len++;
+	co = malloc(len * sizeof(t_coords));
+	i = 0;
+	while(split[i])
+	{
+		co[i] = parse_line(split[i]);	
+		i++;
+	}
+	return(get_biggest_area(co, len));
+}
+// 4604141472 >
+// 4604141472 :/ 
+// 4501110590 >
+// 1588990708