algorithm.c
author viric@llimona
Sun, 07 May 2006 16:28:04 +0200
changeset 17 7c1e68c17c0e
parent 16 fe078fb2e8b4
child 21 e73048967870
permissions -rw-r--r--
Corrected some bugs. Now the algorithm should work for 1-level dependencies.
(that's how it seems)
#include <assert.h>
#include <string.h>
#include <stdio.h> /**********************************PROVA */
#include "general.h"

/* Variables related to the showing of information by os */
extern float percent_to_show;
extern int depth_to_show;

extern int max_depth;
extern int min_depth_period;
extern int max_depth_period;
extern struct Map * actual_map;

/* Prototipes */
static Bool are_there_fixed_boxes(struct Map *m,
	struct BoxMove movements[MAX_MOVES], int *num_movements);
static void force_move_box(struct Map *m, const struct BoxMove move);
static Bool search_did_found(struct Map maps[], int depth,
	struct BoxMove movements[],
	int num_movements, float percent, float total_percent);
static void fill_deps(struct Map *m);

#if 0 /*** THIS IS AN ERROR!!!  The box_will_be_blocked function doesn't work!*/
 Situation:
    
  ->@$ #
      $
*/
int box_will_be_blocked(const struct Map * m, const struct Position mov,
	const struct Position box_pos)
{
	struct Position next_pos2, tmp, tmp2[2];
	int i;

	next_pos2.x = box_pos.x + mov.x;
	next_pos2.y = box_pos.y + mov.y;

	tmp.x = next_pos2.x + mov.x;
	tmp.y = next_pos2.y + mov.y;
	tmp2[0].x = next_pos2.x + mov.y;
	tmp2[0].y = next_pos2.y + mov.x;
	tmp2[1].x = next_pos2.x - mov.y;
	tmp2[1].y = next_pos2.y - mov.x;
	for (i=0; i < 2; i++)
	{
		if (m->man_moves[tmp.y][tmp.x] == WALL &&
			m->man_moves[tmp2[i].y][tmp2[i].x] == BOX)
		{
			return TRUE;
		}
		else if (m->man_moves[tmp.y][tmp.x] == BOX &&
			m->man_moves[tmp2[i].y][tmp2[i].x] == WALL)
		{
			return TRUE;
		}
		else if (m->man_moves[tmp.y][tmp.x] == BOX &&
			m->man_moves[tmp2[i].y][tmp2[i].x] == BOX)
		{
			return TRUE;
		}
	}

	return FALSE;
}

int is_corner_area(const struct Map * m, const struct Position p,
	const struct Position box, const struct Position new_box)
{
	int NumMoves, NewMoves;
	struct Position pos[MAX_MOVES];
	struct Position new_pos[MAX_MOVES];
	char corners[MAX_Y][MAX_X];
	int i,j;
	struct Position next_pos;
	char *next_cell;


	/* Blank the garden */
	for (j = 0; j<m->SizeY; j++)
		for (i=0; i<m->SizeX; i++)
			corners[j][i] = m->Cells[j][i];

	/* Let's put the boxes */
	for (i = 0; i<m->NumBoxes; i++)
		corners[m->Box[i].y][m->Box[i].x] = BOX;

	/* Let's put our box - it can be simply added */
	corners[new_box.y][new_box.x] = BOX;
	/* Let's remove the original box. */
	corners[box.y][box.x] = BLANK;

	NewMoves = 1;
	new_pos[0] = p;
	while (NewMoves > 0)
	{
		/* The before named "New Moves" become the moves we have
		   to analyze */
		NumMoves = NewMoves;
		for (i=0; i<NewMoves; i++)
		{
			pos[i] = new_pos[i];
		}

		/* Search new positions for each position */
		NewMoves = 0;
		for (i=0; i<NumMoves; i++)
		{
			/* For each direction */
			for (j=0; j<4; j++)
			{
				next_pos.x = pos[i].x + move_vectors[j].x;
				next_pos.y = pos[i].y + move_vectors[j].y;
				next_cell = &corners[next_pos.y][next_pos.x];
				if(*next_cell == BLANK ||
					*next_cell == PLATFORM)
				{
					return FALSE;
				}
				else if(*next_cell == CORNER)
				{
					new_pos[NewMoves] = next_pos;
					*next_cell = MANCANMOVE;
					NewMoves++;
				}
			}
		}
	}

	return TRUE;
}

int does_box_close_corners(const struct Map * m, const struct Position mov,
	const struct Position box_pos)
{
	struct Position p, p2;

	p.x = box_pos.x + mov.x;
	p.y = box_pos.y + mov.y;
	
	/* Let's plan the checks */
	/* The point will be marked with a MANCANMOVE */
	p2.x = p.x + mov.x;
	p2.y = p.y + mov.y;
	if (m->Cells[p2.y][p2.x] == CORNER)
	{
		if (is_corner_area(m, p2, box_pos, p))
			return TRUE;
	}

	p2.x = p.x + mov.y;
	p2.y = p.y + mov.x;
	if (m->Cells[p2.y][p2.x] == CORNER)
	{
		if (is_corner_area(m, p2, box_pos, p))
			return TRUE;
	}

	p2.x = p.x - mov.y;
	p2.y = p.y - mov.x;
	if (m->Cells[p2.y][p2.x] == CORNER)
	{
		if (is_corner_area(m, p2, box_pos, p))
			return TRUE;
	}
	return FALSE;
}
#endif


static void force_move_box(struct Map *m, const struct BoxMove move)
{
	struct Position newpos;


	/* Add coords */
	newpos.x = m->Box[move.box].x + move.dir.x;
	newpos.y = m->Box[move.box].y + move.dir.y;

	/* Be certain the move can be done */
	assert(m->Cells[newpos.y][newpos.x] != BOX);
	assert(m->Cells[newpos.y][newpos.x] != WALL);

	/* Control if we moved the box to a platform */
	if(m->Cells[newpos.y][newpos.x] == PLATFORM)
	{
		m->NumBoxesInPlatform++;
	}

	/* Control if we moved the box from a platform */
	if (m->Cells[m->Box[move.box].y][m->Box[move.box].x] == PLATFORM)
	{
		m->NumBoxesInPlatform--;
	}
	m->Man = m->Box[move.box];

	m->Box[move.box] = newpos;
}



static Bool search_did_found(struct Map maps[], int depth,
	struct BoxMove movements[],
	int num_movements, float percent, float total_percent)
{
	struct BoxMove new_movements[MAX_MOVES];
	int num_new_movements;
	struct Map *m; 
	int i;
	float next_percent;

	next_percent = percent / num_movements;

	m = &maps[depth+1];
	if (depth > max_depth)
		max_depth = depth;
	if (depth > max_depth_period)
		max_depth_period = depth;
	if (depth < min_depth_period)
		min_depth_period = depth;

	for (i=0; i < num_movements; i++)
	{
		CopyMap(m, &maps[depth]);
		force_move_box(m, movements[i]);
		/* Let's see if we finished */
		if (m->NumPlatforms == m->NumBoxesInPlatform)
		{
			PrintMove(movements[i]);
			actual_map = &maps[depth+1];
			show_percent_and_map();
			return TRUE;
		}

		if (is_new_map(maps, depth+1))
		{
			fill_deps(m);
			if (are_there_fixed_boxes(m,
				new_movements, &num_new_movements))
			{
				/* That means that the map is illegal */
				/* Maybe we could update the percent here... */
				continue;
			}
			actual_map = &maps[depth+1];
#ifdef DEBUG		/* to be out */
			show_percent_and_map();
#endif
			/* the assert should be IN the function before,
			   before OVERfilling new_movements */
			assert(num_new_movements < MAX_MOVES);
		}
		else
			num_new_movements = 0;

		if (num_new_movements == 0)
		{
			percent_to_show = total_percent + next_percent*i;
			depth_to_show = depth;
		}
		else
		{
			if (depth+1 < MAX_STEPS)
			{
				if(search_did_found(maps, depth+1, new_movements,
					num_new_movements, next_percent,
					total_percent + next_percent*i) == TRUE)
				{
					PrintMove(movements[i]);
					actual_map = &maps[depth+1];
					show_percent_and_map();
					return TRUE;
				}
			}
		}
	}
	return FALSE;
}


/* It only fills the m->man_moves structure */
static void paint_mancanmove(struct Map *m)
{
	struct Position pos[MAX_MOVES];
	struct Position new_pos[MAX_MOVES];
	int NumMoves, NewMoves;
	int j, i;
	struct Position next_pos;
	char *next_cell;

	/* Let's  the map with only walls in man_moves - other, blanks */
	for (j = 0; j<m->SizeY; j++)
		for (i=0; i<m->SizeX; i++)
		{
			if (m->Cells[j][i] == WALL)
				m->man_moves[j][i] = WALL;
			else
				m->man_moves[j][i] = BLANK;
		}

	/* Let's put the boxes */
	for (i = 0; i<m->NumBoxes; i++)
	{
		m->man_moves[m->Box[i].y][m->Box[i].x] = WALL;
	}

	NewMoves = 1;
	new_pos[0].x = m->Man.x;
	new_pos[0].y = m->Man.y;
	m->man_moves[m->Man.y][m->Man.x] = MANCANMOVE;
	while (NewMoves > 0)
	{
		/* The before named "New Moves" become the moves we have
		   to analyze */
		NumMoves = NewMoves;
		for (i=0; i<NewMoves; i++)
		{
			pos[i] = new_pos[i];
		}

		/* Search new positions for each position */
		NewMoves = 0;
		for (i=0; i<NumMoves; i++)
		{
			/* For each direction */
			for (j=0; j<4; j++)
			{
				next_pos.x = pos[i].x + move_vectors[j].x;
				next_pos.y = pos[i].y + move_vectors[j].y;
				next_cell = &m->man_moves[next_pos.y][next_pos.x];
				if(*next_cell == BLANK)
				{
					new_pos[NewMoves] = next_pos;
					*next_cell = MANCANMOVE;
					NewMoves++;
				}
			}
		}
	}
}

/* Returns TRUE if there are fixed boxes that should be moved, FALSE otherwise*/
/* For 'm' it modifies only m->boxes[][] */
static Bool are_there_fixed_boxes(struct Map *m,
	struct BoxMove movements[MAX_MOVES], int *num_movements)
{
	int i,j;
	enum e_direction d;

	/* Box dependencies. The first depends on seconds. */
	struct
	{
		Bool box[MAX_BOXES][MAX_BOXES];
		int ndeps[MAX_BOXES];
	} dep;

	/* Free boxes' arrays */
	struct
	{
		Bool box_is_free[MAX_BOXES]; /* This is only used in 'free' */
		int box[MAX_BOXES];
		int n;
	} free,			/* List of all boxes free-to-move */
		new_free,	/* List of boxes for the next loop (code) */
		tfree;	/* List of boxes of the loop (code) */

	struct Position tpos;

	Bool is_not_set_free;

	/* Initialize to 0 the dependency structures */
	memset((void *) &dep, 0, sizeof(dep));
	new_free.n=0;
	for(i=0; i<m->NumBoxes; i++)
	{
		new_free.box[i] = FALSE;
	}

	/* Let's fill the structure */
	for(i=0; i<m->NumBoxes; i++)
	{
		/* See if the box is blocked. That could be
		   done in fill_deps */
		if (m->box_deps[i].dep_dir[0] == BLOCKED &&
			m->box_deps[i].dep_dir[1] == BLOCKED &&
			m->box_deps[i].dep_dir[2] == BLOCKED &&
			m->box_deps[i].dep_dir[3] == BLOCKED )
		{
			if (m->Cells[m->Box[i].y][m->Box[i].x] !=
				PLATFORM)
				return TRUE;
			/* This is not used actually 
			else
				m->boxes[m->Box[i].y][m->Box[i].x] =
					WALL;
			*/
		}
		/* Let's take note of the dependencies */
		is_not_set_free = TRUE;
		for(d=0; d<4; d++)
		{
			if(m->box_deps[i].dep_dir[d] >= 0)
			{
				if (!dep.box[i][m->box_deps[i].dep_dir[d]])
				{
					dep.box[i][m->box_deps[i].dep_dir[d]] =
						TRUE;
					dep.ndeps[i]++;
				}
			} else
			if(m->box_deps[i].dep_dir[d] == FREE)
			{
				if (is_not_set_free)
				{
					new_free.box[new_free.n++] = i;
					is_not_set_free = FALSE;
				}
			}
		}
	}

	/* Let's analyze if the free boxes can really be moved, and
	   set them as dependant, if they're dependant.
	   If some can be really moved, we should know _where to_. */

	/* Paint MANCANMOVE at each cell the man can reach */
	paint_mancanmove(m);
	
	/* For each free movable box, let's see if the man can reach them
	   fine. If we can, add it to the possible movements. */
	*num_movements=0;
	for(i=0; i<new_free.n; i++)
	{
		/* For each direction, try if the box can be moved */
		for(d=0; d<4; d++)
		{
			if(m->box_deps[new_free.box[i]].dep_dir[d] == FREE)
			{
				add_position3(tpos, m->Box[new_free.box[i]], move_vectors[OPPOSITE_DIR(d)])
				if (m->man_moves[tpos.y][tpos.x] == MANCANMOVE)
				{
					movements[*num_movements].box =
						new_free.box[i];
					movements[*num_movements].dir =
						move_vectors[d];
					(*num_movements)++;
				}
				/* ELSE - we should catch those cases,
				where free boxes cannot be moved. Will they
				ever be movable? 
				THIS HAS TO BE IMPROVED */
			}
		}
	}


	/* ---------------- The next possible movements have been calculated --
	We can still find that this map is illegal. We need to find
	further more if there are boxes unmovable (due to dependencies) */

	/* Let's take out all dependencies from 'free' boxes */
	/* Prepare the 'free' list */
	for(i=0; i<m->NumBoxes;i++)
		free.box_is_free[i] = FALSE;
	free.n = new_free.n;
	for(i=0; i<new_free.n; i++)
	{
		free.box[i] = new_free.box[i];
		free.box_is_free[new_free.box[i]] = TRUE;
	}

	/* KACXO-loop  */
	while (new_free.n > 0)
	{
		/* Copy new_free into free */
		tfree.n = new_free.n;
		for(i=0; i<new_free.n; i++)
			tfree.box[i] = new_free.box[i];
		new_free.n = 0;

		for(i=0; i<tfree.n; i++)
		{
			for(j=0; j<m->NumBoxes; j++)
			{
				/* The box j no more depends on
				   the box tfree[i] */
				if(dep.box[j][tfree.box[i]])
				{
					dep.box[j][tfree.box[i]] = FALSE;
					dep.ndeps[j]--;
					assert(dep.ndeps[j] >= 0);
					if (dep.ndeps[j] == 0 &&
						!free.box_is_free[tfree.box[i]])
					{
						new_free.box[new_free.n++]=j;
						free.box[free.n++]=j;
					}
				}
			}
		}
	}

	/* Now are left only boxes which depend on others-non-free */
	for(i=0; i<m->NumBoxes; i++)
	{
		for(j=0; j<m->NumBoxes; j++)
		{
			/* We only do one-level search !!! */
			/* If the box only depends on another,
			   which also only depends on this... */
			if (dep.box[i][j] && dep.ndeps[i] == 1
				&& dep.box[j][i] && dep.ndeps[j] == 1)
			{
				if (m->Cells[m->Box[i].y][m->Box[i].x]!=
					PLATFORM)
				{
					return TRUE;
				}
				/* We don't set any wall here, they're not
				   important */
			}
		}
	}

	return FALSE;
}

static void init_cell_boxes(struct Map *m)
{
	int i,j;

	/* Let's  the map with only walls in man_moves - other, blanks */
	for (j = 0; j<m->SizeY; j++)
		for (i=0; i<m->SizeX; i++)
			m->cells_boxes[j][i] = -1;

	for(i=0; i<m->NumBoxes; i++)
	{
		m->cells_boxes[m->Box[i].y][m->Box[i].x] = i;
	}
}

/* It fills only m->box_deps */
static void fill_deps(struct Map *m)
{
	int i;
	enum e_direction dir;
	struct Position n; /* Position next to the box */

	/* TO BE OPTIMIZED - get into force_move_box */
	init_cell_boxes(m);

	for(i=0; i<m->NumBoxes; i++)
	{
		/* Initialize the move freedom */
		for(dir=0;dir<4; dir++)
		{
			m->box_deps[i].dep_dir[dir] = FREE;
		}

		/* Limit the freedom */
		for(dir=0;dir<4; dir++)
		{
			add_position3(n,m->Box[i],move_vectors[dir]);
			if(m->Cells[n.y][n.x] == WALL)
			{
				/* IMPROVEMENT: The fixed-box detection
				could be done here */
				m->box_deps[i].dep_dir[dir] = BLOCKED;
				m->box_deps[i].dep_dir[OPPOSITE_DIR(dir)] =
					BLOCKED;
				continue;
			}

			/* if there is Wall limit, we don't want to set box
			   dependency */
			if(m->box_deps[i].dep_dir[dir] == WALL)
				continue;

			/* Put the box dependency in the list */
			if(m->cells_boxes[n.y][n.x] >= 0)
			{
				m->box_deps[i].dep_dir[dir] =
					m->cells_boxes[n.y][n.x];
				/* If the other site is not limited by another
				   box, we set it up too. */

				/* *** MAYBE IT'S BETTER NOT TO SET IT */
				if(m->box_deps[i].dep_dir[OPPOSITE_DIR(dir)]
					== FREE)
				{
				m->box_deps[i].dep_dir[OPPOSITE_DIR(dir)] =
					m->cells_boxes[n.y][n.x];
				}
				continue;
			}
			if(m->Cells[n.y][n.x] == CORNER)
				m->box_deps[i].dep_dir[dir] = BLOCKED;
				
		}
	}
}


int solve_map(const struct Map origin)
{
	struct Map maps[MAX_STEPS+1];
	struct BoxMove new_movements[MAX_MOVES];
	int num_new_movements;

	CopyMap(&maps[0], &origin);

	fill_deps(&maps[0]);
	/* Initializing actual_map here AT LEAST gives protection against
	SIGSEGV */
	assert(!are_there_fixed_boxes(&maps[0], new_movements,
		&num_new_movements));
	search_did_found(maps, 0, new_movements, num_new_movements, 100, 0);

	return 0;
}