User:Eriksiers/Maze generation
These two short programs generate mazes using a random walk. I didn't put them up as solutions to Maze generation because that task requires the use of the depth-first algorithm, which is much faster than what I've done here.
Text
This uses # for walls and . for floors.
<lang qbasic>OPTION BASE 1
CONST scrW = 80 CONST scrH = 50
WIDTH scrW, scrH
RANDOMIZE TIMER
TYPE cell
x AS INTEGER y AS INTEGER
END TYPE
DIM working AS cell, old AS cell
working.x = (INT(RND * scrW) AND -2) working.y = (INT(RND * scrH) AND -2)
'Fill with walls: FOR y = 1 TO scrH
PRINT STRING$(79, "#");
NEXT
'Random walk: DO
chk = chk + 1
'This check really slows the program down, so we only do it every 100 iterations.
IF (chk MOD 100) = 0 THEN
chk = 0
FOR x = 2 TO scrW - 2 STEP 2
FOR y = 2 TO scrH - 2 STEP 2
IF SCREEN(y, x) = 35 THEN GOTO cntT
NEXT
NEXT
EXIT DO
END IF
cntT:
old = working
'The IFs inside the SELECT CASE ensure that drawing doesn't happen off the screen.
SELECT CASE INT(RND * 4)
CASE 0
working.x = working.x + 2
IF working.x >= scrW THEN working.x = working.x - 4
CASE 1
working.y = working.y + 2
IF working.y >= scrH THEN working.y = working.y - 4
CASE 2
working.x = working.x - 2
IF working.x < 1 THEN working.x = working.x + 4
CASE 3
working.y = working.y - 2
IF working.y < 1 THEN working.y = working.y + 4
END SELECT
IF SCREEN(working.y, working.x) = 35 THEN
LOCATE working.y, working.x
PRINT ".";
LOCATE (old.y + working.y) \ 2, (old.x + working.x) \ 2
PRINT ".";
END IF
IF INKEY$ <> "" THEN EXIT DO
LOOP</lang>
The generated mazes look like this:
############################################################################### #.#...#.#.#.#.#.#.#.....#.#...#.....#.......#...#.#.#.#.#.....#...#.#.#.......# #.###.#.#.#.#.#.#.#.#####.#.#.###.#####.#######.#.#.#.#.#####.###.#.#.#.####### #...#.....#.#.#...........#.#.#.................#...#...#...........#.......#.# #.###.###.#.#.#.###.#########.###.#.#.#########.#.###.#####.###.###.#.###.#.#.# #.#.#.#...#.....#.#.#.....#.....#.#.#.....#...#...#...#...#.#.#.#.#...#...#.#.# #.#.#.###.###.#.#.#.###.###.#.###.#.#####.#.###.###.#.###.###.#.#.#####.#####.# #.#...#.......#...#.....#.#.#.#.#.#.....#.....#.....#...........#.....#.#.....# #.#.###.#######.#.#####.#.#.#.#.#######.###.###.#############.###.#########.### #.#...#...#.....#.#.........#.#.#.#.......#.#...#.......#...#.#...#.#.....#.#.# #.#.###.#########.#####.###.###.#.#.#.#####.###.#.#.#######.#.###.#.#####.#.#.# #.....#...#...#.#.#...#.#.#.#.....#.#.....#...#.#.#.......#.#.....#.#...#...#.# #####.#######.#.###.#.#.#.#####.###.#.#####.#.###.#####.###.#####.#.###.#.###.# #.....#.......#.....#...#.......#.#.#.....#.#.#.....#.......#.#.#...#.........# #.###.###.#.###.#.###.#####.###.#.#.#####.###.###.#.#####.###.#.#.###.###.###.# #.#...#...#.#...#...#.....#.#.....#.....#...#...#.#...#.............#...#...#.# ###.###.###########.#####.#####.###.#######.#######.#.#.#######.#.###.###.##### #.#...#...#.#.........#.#.#...#...#.#.#.#.....#.#...#.#...#.....#...#.#.#.....# #.#.#.#.#.#.###.#.###.#.#.#.###.#####.#.#.#.###.###.###.###.#.###.#####.#.#.### #...#.#.#.....#.#.#.....#.#.#...#.#...#.#.#.#.....#.#.....#.#.#.#.#.#.....#...# #.###########.###.#####.###.###.#.###.#.###.###.#####.#.#####.#.###.#.###.###.# #.....#.#.........#.........#.#.#.#...#...#.#.......#.#...#...........#.#...#.# #.#####.#.###.###.#.#####.#.#.#.#.#.#.#.#.###.#####.#.#######.#.#.#.#.#.#.##### #.#.....#.#.....#.#...#.#.#.#.#.....#...#.......#...#...#.#.#.#.#.#.#.#...#...# ###.###.###.###.###.###.#.#.#.#.#######.###.#.###.###.###.#.#.###.###.#######.# #...#.#.....#...#.....#.#.#...#.#...#.#.#...#.#...#.......#...#.....#.#...#...# ###.#.#####.###.#####.#.###.#.#.###.#.###.###.###.#######.#########.#.#.#.#.#.# #...#.#.....#...#.#.....#...#.#.#...#.#.#.#...#...#.#.......#...#...#.#.#...#.# #####.###.#######.#####.###.#.#####.#.#.#######.#.#.#########.###.#.###.#.##### #.......#.......#.....#.#...#.#.......#...#.....#.....#.....#.#...#...#.#...#.# ###.#####.#####.#.#.#.###.###.###.#####.#########.###.#.#.###.#.###.#.###.###.# #.#.........#...#.#.#.#.#...#.....#.#.......#.#.....#...#.#.....#...#...#...#.# #.###.###.#.#.###.#####.###.#####.#.#######.#.#.#.#.###.###.#####.###.###.#.#.# #.....#...#.#...#...#.#...#.#.#.#.......#.#.....#.#.#...#...#.......#.#.#.#.#.# #.#######.#####.###.#.#.###.#.#.#######.#.###.#########.###.###########.#.###.# #.......#.#.......#.........#.#...#.............#.#.#.......#.......#.#.....#.# #####.#####.###.#.###.###.#.#.#.#########.#.#.###.#.###.#####.#.###.#.###.###.# #.........#...#.#.#.#.#...#.....#.....#...#.#...#.#.#.#.#.#.#.#.#.#.....#...#.# #.#.###.#########.#.#################.#########.#.#.#.###.#.#.###.###.#.#.###.# #.#...#.....#.#.#.#...#.....#...#.....#...#.......#.........#...#...#.#...#...# #######.#.###.#.#.#.###.#####.#.#####.#.###.#.#######.#######.###.###.#####.### #.#.....#.#.#.....#.#.#.......#.#.....#.#.#.#...#.....#...........#...#...#...# #.###.#####.#.#.#.#.#.#.###.###.#.#####.#.#####.#.###.#.###.#.#####.#.#.###.### #.#.....#...#.#.#.#.#...#.#.#...#...#.#...#.#.....#...#...#.#.#...#.#.....#...# #.#.#######.###.#.#.#.#.#.#.###.###.#.#.###.###.#####.#.###.###.#.#.###.#.#.### #.....#.......#.#...#.#.#.#.#.#...........#.......#...#...#.#...#...#...#.....# #####.#.###.#.#.#.###.###.###.#####.#####.###.#.###.#############.###.#.#.###.# #.........#.#.#.#.#...............#.....#.....#...#...............#...#.#...#.# ###############################################################################
Graphical
This is a graphical variation of the above. It uses white for floors and black for walls. FreeBASIC is required due to how I write the results to the image file. (This works under QBasic aside from the very last line. Changing that would let it work under any QB-alike.)
<lang qbasic>OPTION BASE 1
CONST scrW = 400 CONST scrH = 300
ScreenRes scrW, scrH
RANDOMIZE TIMER
TYPE cell
x AS INTEGER y AS INTEGER
END TYPE
DIM working AS cell, old AS cell
working.x = (INT(RND * scrW) AND -2) working.y = (INT(RND * scrH) AND -2)
'random walk DO
chk = chk + 1
IF (chk MOD 1000) = 0 THEN
chk = 0
FOR x = 0 TO (scrW - 1) STEP 2
FOR y = 0 TO (scrH - 1) STEP 2
IF POINT(x, y) = 0 THEN GOTO cntT
NEXT
NEXT
EXIT DO
END IF
cntT:
old = working
SELECT CASE INT(RND * 4)
CASE 0
working.x = working.x + 2
IF working.x >= scrW THEN working.x = working.x - 4
CASE 1
working.y = working.y + 2
IF working.y >= scrH THEN working.y = working.y - 4
CASE 2
working.x = working.x - 2
IF working.x < 0 THEN working.x = working.x + 4
CASE 3
working.y = working.y - 2
IF working.y < 0 THEN working.y = working.y + 4
END SELECT
IF (POINT(working.x, working.y)) = 0 THEN LINE (old.x, old.y)-(working.x, working.y), 15
IF INKEY$ <> "" THEN EXIT DO
LOOP
BSAVE "maze.bmp", 0</lang>