131 lines
3.8 KiB
C
131 lines
3.8 KiB
C
#include <stdio.h>
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#include <string.h>
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#include "maze.h"
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#include <assert.h>
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#include <unistd.h>
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#define CHECKED_BIT 16
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#define DIRECTION_BITS 15
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enum direction {
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NORTH = 8,
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EAST = 4,
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SOUTH = 2,
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WEST = 1,
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NONE = 0
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};
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int solve_maze(char* maze, int size) {
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if (maze[0] == 'x') {
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return 0;
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}
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printf("\n");
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char maze2d[size][size];
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for (int y = 0; y < size; y++) {
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for (int x = 0; x < size; x++) {
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printf("%c", maze[size * y + x]);
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maze2d[y][x] = maze[size * y + x] == 'x' ? 'x' : 0;
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}
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printf("\n");
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}
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printf("\nend %d\n\n", size);
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int posY = 0, posX = 0;
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while (1) {
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enum direction next_step;
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if (posX + 1 < size && maze2d[posY][posX + 1] != 'x' && !(maze2d[posY][posX + 1] & CHECKED_BIT)) {
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next_step = EAST;
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} else if (posY + 1 < size && maze2d[posY + 1][posX] != 'x' && !(maze2d[posY + 1][posX] & CHECKED_BIT)) {
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next_step = SOUTH;
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} else if (posX - 1 >= 0 && maze2d[posY][posX - 1] != 'x' && !(maze2d[posY][posX - 1] & CHECKED_BIT)) {
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next_step = WEST;
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} else if (posY - 1 >= 0 && maze2d[posY - 1][posX] != 'x' && !(maze2d[posY - 1][posX] & CHECKED_BIT)) {
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next_step = NORTH;
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} else {
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next_step = NONE;
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}
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if (next_step != NONE) {
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maze2d[posY][posX] |= CHECKED_BIT;
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switch (next_step) {
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case EAST:
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posX += 1;
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maze2d[posY][posX] |= WEST;
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break;
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case SOUTH:
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posY += 1;
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maze2d[posY][posX] |= NORTH;
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break;
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case WEST:
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posX -= 1;
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maze2d[posY][posX] |= EAST;
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break;
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case NORTH:
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posY -= 1;
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maze2d[posY][posX] |= SOUTH;
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break;
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default:
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break;
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}
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} else {
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char came_from = maze2d[posY][posX] & DIRECTION_BITS;
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maze2d[posY][posX] = CHECKED_BIT;
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switch (came_from) {
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case EAST:
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posX += 1;
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break;
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case SOUTH:
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posY += 1;
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break;
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case WEST:
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posX -= 1;
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break;
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case NORTH:
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posY -= 1;
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break;
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default:
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break;
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}
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}
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if (posX == 0 && posY == 0) {
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return 0;
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} else if (posX == size - 1 && posY == size - 1) {
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maze2d[0][0] = '*';
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//cleanup data bits
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for (int y = 0; y < size; y++) {
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for (int x = 0; x < size; x++) {
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if (maze2d[y][x] == CHECKED_BIT || maze2d[y][x] == 0) {
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maze2d[y][x] = ' ';
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} else if (maze2d[y][x] != 'x') {
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maze2d[y][x] = '*';
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}
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}
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}
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//cleanup redundant routes
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for (int y = size - 2; y >= 0; y--) {
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for (int x = size - 2; x >= 0; x--) {
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if (maze2d[y][x] == '*' && maze2d[y + 1][x] == '*' && maze2d[y + 1][x + 1] == '*' && maze2d[y][x + 1] == '*') {
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maze2d[y + 1][x + 1] = ' ';
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maze2d[y][x + 1] = ' ';
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}
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}
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}
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//serialize
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for (int y = 0; y < size; y++) {
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for (int x = 0; x < size; x++) {
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maze[y * size + x] = maze2d[y][x];
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}
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}
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return 1;
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}
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}
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}
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