Comments

Makefile

@@ -0,0 +1,88 @@
+SRC = main.c \
+		io.c \
+		parsing.c \
+		parsing_simple.c \
+		solution.c \
+		printing.c \
+		map_helpers.c \
+		ft_string.c \
+
+HEADERS = parsing.h \
+			printing.h \
+			solution.h \
+			ft_string.h \
+
+OBJDIR = obj
+SRCDIR = srcs
+INCDIR = includes
+
+CC = cc
+CFLAGS = \
+		-Wall \
+		-Wextra \
+		-Werror \
+		-I$(INCDIR) \
+		-fcolor-diagnostics \
+
+LDFLAGS =
+
+_OBJ = $(SRC:.c=.o)
+OBJ = $(addprefix $(OBJDIR)/,$(_OBJ))
+DEPS = $(addprefix $(INCDIR)/,$(HEADERS))
+
+RM = /bin/rm -f
+RMDIR = /bin/rmdir
+
+.DEFAULT_GOAL = test
+
+NAME ?= bsq
+
+.PHONY: re fclean clean all
+
+all: $(NAME)
+
+clean:
+	@$(RM) $(OBJ)
+
+fclean: clean
+	@$(RM) $(NAME)
+	@$(RMDIR) $(OBJDIR) 2>/dev/null || true
+
+re: fclean all
+
+$(NAME): $(OBJ)
+	@$(CC) $(LDFLAGS) $^ -o $@
+
+$(OBJ): | $(OBJDIR)
+
+$(OBJDIR)/%.o: $(SRCDIR)/%.c $(DEPS)
+	@norminette $< >/dev/null || { printf '\033[101;37m%s\033[m\n' "!Norminette Failed>>>"; norminette $<; printf '\033[101;37m%s\033[m\n' "<<<Norminette Failed!"; exit 1; }
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+$(OBJDIR):
+	@mkdir -p $@
+
+tests: test
+
+test: re run fclean
+
+SUCCESS_MSG =      printf '\n\033[102;30m --- %s --- \033[m\n\n' "Test passed!"
+FAIL_MSG =         printf '\n\033[101;37m --- %s --- \033[m\n\n' "Test failed!"
+SUCCESS_MSG_VALG = printf '\n\033[102;30m --- %s --- \033[m\n\n' "Valgrind ran without errors!"
+FAIL_MSG_VALG =    printf '\n\033[101;37m --- %s --- \033[m\n\n' "Valgrind Failed!"
+SUCCESS =          && $(SUCCESS_MSG)      || $(FAIL_MSG)
+SUCCESS_VALG =     && $(SUCCESS_MSG_VALG) || $(FAIL_MSG_VALG)
+FAIL =             && $(FAIL_MSG)         || $(SUCCESS_MSG)
+VALGRIND =         valgrind --leak-check=full --error-exitcode=1
+VALGRIND_SMALL =   2>/dev/null 1>&2 valgrind --leak-check=full --error-exitcode=1
+YLW =              : ;
+CYN =              : ;
+CLR_RST =          && : 
+
+run:
+	@#clear
+	$(CYN) $(VALGRIND_SMALL) ./$(NAME) $(CLR_RST) $(SUCCESS_VALG)
+	$(YLW) ./$(NAME) $(CLR_RST) $(SUCCESS)
+
+valgrind: re
+	$(CYN) $(VALGRIND) ./$(NAME) $(CLR_RST) $(SUCCESS_VALG)

assets/map1

@@ -1,11 +0,0 @@
-10.X#
-.X......X.........X.
-.X...X......X.X.....
-X..X......X........X
-....X..X...X........
-.......X........X.X.
-......X......X......
-.............X......
-..X.X..........X....
-..........X.........
-...X.........X..X.X.

assets/map2

@@ -1,11 +0,0 @@
-10.X#
-.XX.....XX..........
-..X...X...X..X......
-X.X......XXXX.......
-.....X..............
-......X...X.......XX
-X...XX.........X.X..
-..................X.
-....X...X..XX....X..
-..............X..X..
-........X......X.X..

assets/map20x40.map

@@ -0,0 +1,21 @@
+20.X#
+........................................
+...................X....................
+.........................X..........X...
+..............X.........................
+.........X...........................X..
+............X..X........................
+..................................X.....
+....................................X...
+........................................
+X.X..........................X..........
+....X.................................X.
+..........X.............................
+.............................X..........
+....................X......X............
+............................X...X......X
+.......X........X....X....X..XX.........
+................X........X............X.
+................X......X................
+....X................X.......X..........
+........................................

assets/map3

@@ -1,11 +0,0 @@
-10.X#
-.........X.X........
-X.....X.......X.....
-.X........XXX..X....
-...X..XX.....X......
-.....X.....X.....X..
-..X.........X....X..
-......X....X.X......
-...........X....X.X.
-XX..................
-....X.....X...X...X.

assets/solve.py

@@ -1,52 +0,0 @@
-#!/usr/bin/env python3
-
-import sys
-
-def main():
-    with open(sys.argv[1]) as b:
-        board = b.read().splitlines()
-    try:
-        first_line = board[0][::-1]
-    except:
-        print("map error")
-        sys.exit(1)
-    board = board[1:]
-    full = first_line[0]
-    obstc = first_line[1]
-    empty = first_line[2]
-    try:
-        num = int(first_line[3:][::-1])
-    except:
-        print("map error")
-        sys.exit(2)
-    if len(board) != num:
-        print("map error")
-        sys.exit(3)
-    first_line_len = len(board[0])
-    if any(first_line_len != len(line) for line in board):
-        print("map error")
-        sys.exit(4)
-    converted_board = []
-    for i, line in enumerate(board):
-        converted_board.append(list(line))
-    for i in range(len(board)):
-        for j in range(first_line_len):
-            val = board[i][j]
-            if i < 1:
-                top = 0
-            else:
-                top = converted_board[i - 1][j]
-            if j < 1:
-                left = 0
-            else:
-                left = converted_board[i][j - 1]
-            if j < 1 or i < 1:
-                top_left = 0
-            else:
-                top_left = converted_board[i - 1][j - 1]
-            converted_board[i][j] = str(int(val == obstc)) + left + top + top_left
-            print(end=converted_board[i][j])
-        print()
-
-if __name__ == '__main__':
-    main()

assets/subject.map

@@ -0,0 +1,10 @@
+9.ox
+...........................
+....o......................
+............o..............
+...........................
+....o......................
+...............o...........
+...........................
+......o..............o.....
+..o.......o................

includes/ft_string.h

@@ -0,0 +1,20 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_string.h                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/05 09:56:45 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 10:02:30 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef FT_STRING_H
+# define FT_STRING_H
+# include <stdio.h>
+
+char	*ft_strcpy(char *dest, char *src);
+size_t	ft_strlen(char const *str);
+
+#endif

includes/parsing.h

@@ -0,0 +1,45 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   parsing.h                                          :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: apago <apago@student.42.fr>                +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/04 18:22:11 by apago             #+#    #+#             */
+/*   Updated: 2023/04/05 09:31:04 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef PARSING_H
+# define PARSING_H
+
+# include "fcntl.h"
+# include "stdio.h"
+# include "stdlib.h"
+# include "unistd.h"
+
+typedef struct Meta
+{
+	char	empty;
+	char	obstacle;
+	char	full;
+	int		height;
+	int		width;
+}			t_meta;
+
+typedef struct Map
+{
+	t_meta	meta;
+	char	*data;
+	char	*copy;
+}			t_map;
+
+char		*read_file(int file);
+size_t		read_uint(char *str);
+int			parse_valid_uint(char *str, size_t len);
+int			read_char(char *str, char *dst);
+int			printable(char c);
+size_t		count_first_line(char *line);
+int			read_fname(char *name, t_map *map);
+
+#endif

includes/printing.h

@@ -0,0 +1,29 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   printing.h                                         :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/05 04:11:08 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 10:01:56 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef PRINTING_H
+# define PRINTING_H
+# include "parsing.h"
+# include <limits.h>
+# include <unistd.h>
+# define RED "\x1b[31m"
+# define GRN "\x1b[32m"
+# define YLW "\x1b[33m"
+# define CLR_RST "\x1b[m"
+
+void	ft_putchar(char c);
+void	ft_putstr(char *str);
+void	ft_putnbr(int nb);
+void	print_map(t_map *map, int as_numbers);
+int		ft_err(char *str, int exit_code);
+
+#endif

includes/solution.h

@@ -0,0 +1,23 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   solution.h                                         :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/05 04:02:35 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 09:05:08 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef SOLUTION_H
+# define SOLUTION_H
+# include "parsing.h"
+# include "printing.h"
+
+void	solve(t_map *map);
+int		itoc(int idx, int width);
+int		itor(int idx, int width);
+char	get_cell(t_map *map, int idx, int top, int left);
+
+#endif

srcs/ft_string.c

@@ -0,0 +1,34 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_string.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/05 09:57:31 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 09:57:39 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "ft_string.h"
+
+char	*ft_strcpy(char *dest, char *src)
+{
+	char	*o_dest;
+
+	o_dest = dest;
+	while (*src)
+		*dest++ = *src++;
+	*dest = 0;
+	return (o_dest);
+}
+
+size_t	ft_strlen(char const *str)
+{
+	size_t	size;
+
+	size = 0;
+	while (*str++)
+		++size;
+	return (size);
+}

srcs/io.c

@@ -0,0 +1,73 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   io.c                                               :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: apago <apago@student.42.fr>                +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/04 18:23:57 by apago             #+#    #+#             */
+/*   Updated: 2023/04/04 18:24:50 by apago            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "parsing.h"
+
+void	copy_bytes(char *dst, char *src, size_t bytes)
+{
+	size_t	i;
+
+	i = 0;
+	while (i < bytes)
+	{
+		dst[i] = src[i];
+		i++;
+	}
+}
+
+int	push_bytes(size_t n_read, char **res, size_t *offset, size_t *size)
+{
+	char	*new_res;
+
+	if (n_read <= 0)
+		return (n_read);
+	*offset += n_read;
+	if (*offset == *size)
+	{
+		new_res = malloc(*size * 2);
+		if (!new_res)
+			return (-1);
+		copy_bytes(new_res, *res, *size);
+		free(*res);
+		*res = new_res;
+		*size *= 2;
+	}
+	return (n_read);
+}
+
+char	*read_file(int file)
+{
+	size_t	size;
+	size_t	offset;
+	size_t	n_read;
+	char	*res;
+
+	offset = 0;
+	size = 1024;
+	res = malloc(size);
+	if (!res)
+		return (0);
+	while (1)
+	{
+		n_read = read(file, &res[offset], size - offset);
+		n_read = push_bytes(n_read, &res, &offset, &size);
+		if (!n_read)
+			break ;
+		if (n_read < 0)
+		{
+			free(res);
+			return (0);
+		}
+	}
+	res[offset] = 0;
+	return (res);
+}

srcs/main.c

@@ -0,0 +1,62 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   main.c                                             :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/04 21:50:50 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 10:18:04 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include <stdio.h>
+#include "solution.h"
+#include "printing.h"
+#include "ft_string.h"
+
+void	debug_set_map(t_map *map)
+{
+	char	*str;
+
+	str = \
+	"........................................" \
+	"...................X...................." \
+	".........................X..........X..." \
+	"..............X........................." \
+	".........X...........................X.." \
+	"............X..X........................" \
+	"..................................X....." \
+	"....................................X..." \
+	"........................................" \
+	"X.X..........................X.........." \
+	"....X.................................X." \
+	"..........X............................." \
+	".............................X.........." \
+	"....................X......X............" \
+	"............................X...X......X" \
+	".......X........X....X....X..XX........." \
+	"................X........X............X." \
+	"................X......X................" \
+	"....X................X.......X.........." \
+	"........................................";
+	map->data = malloc(sizeof(char) * (ft_strlen(str) + 1));
+	ft_strcpy(map->data, str);
+}
+
+int	main(void)
+{
+	t_map	map;
+
+	if (!read_fname("./assets/map20x40.map", &map))
+		return (ft_err("map error\n", 1));
+	free(map.data);
+	debug_set_map(&map);
+	map.copy = malloc(sizeof(char) * (ft_strlen(map.data) + 1));
+	ft_strcpy(map.copy, map.data);
+	solve(&map);
+	print_map(&map, 0);
+	free(map.data);
+	free(map.copy);
+	return (0);
+}

srcs/map_helpers.c

@@ -0,0 +1,45 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   map_helpers.c                                      :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/05 06:50:28 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 09:05:18 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "solution.h"
+
+// index to column
+int	itoc(int idx, int width)
+{
+	return (idx % width);
+}
+
+// index to row
+int	itor(int idx, int width)
+{
+	return (idx / width);
+}
+
+char	get_cell(t_map *map, int idx, int bottom, int right)
+{
+	int	row;
+	int	col;
+
+	if ((bottom | right) == 0)
+		return (map->data[idx]);
+	row = itor(idx, map->meta.width);
+	col = itoc(idx, map->meta.width);
+	row += bottom;
+	col += right;
+	if (row >= map->meta.height
+		|| col >= map->meta.width
+		|| col < 0
+		|| row < 0)
+		return (0);
+	idx = col + row * map->meta.width;
+	return (map->data[idx]);
+}

srcs/parsing.c

@@ -0,0 +1,123 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   parsing.c                                          :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: apago <apago@student.42.fr>                +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/04 16:19:27 by apago             #+#    #+#             */
+/*   Updated: 2023/04/05 10:04:09 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "parsing.h"
+
+int	parse_meta(char *str, t_meta *meta)
+{
+	int	read_bytes;
+
+	read_bytes = read_uint(str);
+	meta->height = parse_valid_uint(str, read_bytes);
+	if (meta->height < 1)
+		return (0);
+	if (!read_char(&str[read_bytes++], &meta->empty))
+		return (0);
+	if (!read_char(&str[read_bytes++], &meta->obstacle))
+		return (0);
+	if (!read_char(&str[read_bytes++], &meta->full))
+		return (0);
+	if (!printable(meta->empty) || !printable(meta->obstacle)
+		|| !printable(meta->full))
+		return (0);
+	if ((meta->empty == meta->obstacle) || (meta->obstacle == meta->full))
+		return (0);
+	if (str[read_bytes++] != '\n')
+		return (0);
+	return (read_bytes);
+}
+
+size_t	parse_line(char *line, char *dst, t_meta *meta)
+{
+	int	i;
+
+	i = 0;
+	while (i < meta->width)
+	{
+		if (!line[i])
+			return (0);
+		if (line[i] == meta->empty)
+			dst[i] = '.';
+		else if (line[i] == meta->obstacle)
+			dst[i] = 'o';
+		else
+			return (0);
+		i++;
+	}
+	if (line[i] != '\n')
+		return (0);
+	return (meta->width + 1);
+}
+
+	// size_t	offset; // unused
+char	*parse_data(char *data, t_meta *meta)
+{
+	char	*res;
+	size_t	read_bytes;
+	int		i;
+
+	i = 0;
+	res = malloc(meta->width * meta->height * sizeof(char));
+	if (!res)
+		return (0);
+	while (i < meta->height)
+	{
+		read_bytes = parse_line(data, res, meta);
+		if (!read_bytes)
+		{
+			free(res);
+			return (0);
+		}
+		data += read_bytes;
+		i++;
+	}
+	if (!*data)
+		return (res);
+	free(res);
+	return (0);
+}
+
+int	parse_input(char *str, t_map *map)
+{
+	size_t	offset;
+	size_t	read_bytes;
+
+	read_bytes = parse_meta(str, &map->meta);
+	if (!read_bytes)
+		return (0);
+	offset = read_bytes;
+	map->meta.width = count_first_line(&str[offset]);
+	if (!map->meta.width)
+		return (0);
+	map->data = parse_data(&str[offset], &map->meta);
+	if (!map->data)
+		return (0);
+	return (1);
+}
+
+int	read_fname(char *name, t_map *map)
+{
+	int		file;
+	char	*text;
+	int		res;
+
+	file = open(name, O_RDONLY);
+	if (file == -1)
+		return (0);
+	text = read_file(file);
+	close(file);
+	if (!text)
+		return (0);
+	res = parse_input(text, map);
+	free(text);
+	return (res);
+}

srcs/parsing_simple.c

@@ -0,0 +1,67 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   parsing_simple.c                                   :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: apago <apago@student.42.fr>                +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/04 18:25:47 by apago             #+#    #+#             */
+/*   Updated: 2023/04/04 21:56:56 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "parsing.h"
+
+size_t	read_uint(char *str)
+{
+	int	i;
+
+	i = 0;
+	while (*str >= '0' && *str <= '9')
+	{
+		str++;
+		i++;
+	}
+	return (i);
+}
+
+int	parse_valid_uint(char *str, size_t len)
+{
+	int		res;
+	size_t	i;
+
+	res = 0;
+	i = 0;
+	while (i < len)
+	{
+		res = res * 10 + str[i] - '0';
+		i++;
+	}
+	return (res);
+}
+
+int	read_char(char *str, char *dst)
+{
+	if (!*str)
+		return (0);
+	*dst = *str;
+	return (1);
+}
+
+int	printable(char c)
+{
+	return (c >= 32 && c <= 127);
+}
+
+size_t	count_first_line(char *line)
+{
+	size_t	cnt;
+
+	cnt = 0;
+	while (*line && *line != '\n')
+	{
+		line++;
+		cnt++;
+	}
+	return (cnt);
+}

srcs/printing.c

@@ -0,0 +1,75 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   printing.c                                         :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/05 04:09:39 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 10:19:12 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "printing.h"
+
+void	ft_putchar(char c)
+{
+	write(1, &c, 1);
+}
+
+int	ft_err(char *str, int exit_code)
+{
+	ft_putstr(RED);
+	ft_putstr(str);
+	ft_putstr(CLR_RST);
+	return (exit_code);
+}
+
+void	ft_putstr(char *str)
+{
+	while (*str)
+		ft_putchar(*str++);
+}
+
+void	ft_putnbr(int nb)
+{
+	if (nb > 9)
+	{
+		ft_putnbr(nb / 10);
+		ft_putchar(nb % 10 + '0');
+	}
+	else if (nb == INT_MIN)
+	{
+		ft_putnbr(nb / 10);
+		ft_putnbr(-(nb % 10));
+	}
+	else if (nb < 0)
+	{
+		ft_putchar('-');
+		ft_putnbr(-nb);
+	}
+	else
+		ft_putchar(nb % 10 + '0');
+}
+
+void	print_map(t_map *map, int as_numbers)
+{
+	int	i;
+	int	j;
+
+	i = -1;
+	while (++i < map->meta.height)
+	{
+		j = -1;
+		while (++j < map->meta.width)
+		{
+			if (as_numbers)
+			{
+				ft_putnbr(map->data[i * map->meta.width + j]);
+			}
+			else
+				ft_putchar(map->data[i * map->meta.width + j]);
+		}
+		ft_putchar('\n');
+	}
+}

srcs/solution.c

@@ -0,0 +1,100 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   solution.c                                         :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/04/04 21:46:57 by tischmid          #+#    #+#             */
+/*   Updated: 2023/04/05 10:31:15 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "solution.h"
+
+// Replace each cell by the number of obstacles a rectangle starting
+// from the top left cell, filling the board until the cell in question,
+// covers. Border is inclusive. This will enable us to check if a given
+// square contains obstacles or not in O(1) time, instead of O(n^2),
+// namely by summing up the corner cells alternatingly (+, -, +, -, clockwise).
+void	preprocess_map(t_map *map)
+{
+	int		is_obstacle;
+	int		idx;
+
+	idx = 0;
+	while (idx < map->meta.width * map->meta.height)
+	{
+		is_obstacle = get_cell(map, idx, 0, 0) == map->meta.obstacle;
+		map->data[idx] = is_obstacle + \
+			get_cell(map, idx, 0, -1) + \
+			get_cell(map, idx, -1, 0) - \
+			get_cell(map, idx, -1, -1);
+		idx++;
+	}
+}
+
+int	count_obstacles(t_map *map, int idx, int sq_size)
+{
+	int	alternat_corner_sum;
+
+	if (sq_size == 0)
+		return (0);
+	if (sq_size == 1)
+		return (get_cell(map, idx, 0, 0));
+	if (idx + (sq_size - 1) * (map->meta.width + 1)
+		> map->meta.width * map->meta.height)
+		return (-1);
+	alternat_corner_sum = get_cell(map, idx, -1, -1) - \
+							get_cell(map, idx, -1, sq_size - 1) + \
+							get_cell(map, idx, sq_size - 1, sq_size - 1) - \
+							get_cell(map, idx, sq_size - 1, -1);
+	return (alternat_corner_sum);
+}
+
+void	fill_with_full(t_map *map, int sq_idx, int sq_size)
+{
+	int	idx;
+	int	idx_row;
+	int	idx_col;
+	int	sq_row;
+	int	sq_col;
+
+	sq_row = itor(sq_idx, map->meta.width);
+	sq_col = itoc(sq_idx, map->meta.width);
+	idx = 0;
+	while (idx < map->meta.width * map->meta.height)
+	{
+		idx_row = itor(idx, map->meta.width);
+		idx_col = itoc(idx, map->meta.width);
+		if (idx_row >= sq_row && idx_row < sq_row + sq_size
+			&& idx_col >= sq_col && idx_col < sq_col + sq_size)
+			map->data[idx] = map->meta.full;
+		else
+			map->data[idx] = map->copy[idx];
+		idx++;
+	}
+}
+
+void	solve(t_map *map)
+{
+	int	idx;
+	int	sq_idx;
+	int	sq_size;
+
+	preprocess_map(map);
+	idx = 0;
+	sq_size = 0;
+	sq_idx = 0;
+	while (idx < map->meta.width * map->meta.height)
+	{
+		while (count_obstacles(map, idx, sq_size) == 0)
+		{
+			sq_idx = idx;
+			sq_size++;
+		}
+		idx++;
+	}
+	sq_size--;
+	fill_with_full(map, sq_idx, sq_size);
+}