A rectangular maze puzzle visualization with clearly marked start and goal positions. The maze is algorithmically generated to guarantee exactly one solution path from start to finish. The clean black-and-white design is optimized for printing, allowing users to solve the puzzle with a pen or pencil.
#' anyplot.ai
#' maze-printable: Printable Maze Puzzle
#' Library: ggplot2 3.5.1 | R 4.4.1
#' Quality: 90/100 | Created: 2026-09-05
library(ggplot2)
library(dplyr)
library(ragg)
set.seed(42)
# --- Theme tokens -------------------------------------------------------
THEME <- Sys.getenv("ANYPLOT_THEME", "light")
PAGE_BG <- if (THEME == "light") "#FAF8F1" else "#1A1A17"
INK <- if (THEME == "light") "#1A1A17" else "#F0EFE8"
INK_MUTED <- if (THEME == "light") "#6B6A63" else "#A8A79F"
IMPRINT_PALETTE <- c(
"#009E73", "#C475FD", "#4467A3", "#BD8233",
"#AE3030", "#2ABCCD", "#954477", "#99B314"
)
# --- Maze generation (randomized depth-first backtracker) ---------------
# A spanning tree over the cell grid guarantees exactly one path between
# any two cells, so start and goal have a single unique solution route.
maze_width <- 22
maze_height <- 22
east_open <- matrix(FALSE, nrow = maze_width, ncol = maze_height)
south_open <- matrix(FALSE, nrow = maze_width, ncol = maze_height)
visited <- matrix(FALSE, nrow = maze_width, ncol = maze_height)
visited[1, 1] <- TRUE
stack <- list(list(x = 0, y = 0))
while (length(stack) > 0) {
cur <- stack[[length(stack)]]
cx <- cur$x
cy <- cur$y
neighbors <- list()
if (cx > 0 && !visited[cx, cy + 1]) {
neighbors[[length(neighbors) + 1]] <- list(x = cx - 1, y = cy, dir = "W")
}
if (cx < maze_width - 1 && !visited[cx + 2, cy + 1]) {
neighbors[[length(neighbors) + 1]] <- list(x = cx + 1, y = cy, dir = "E")
}
if (cy > 0 && !visited[cx + 1, cy]) {
neighbors[[length(neighbors) + 1]] <- list(x = cx, y = cy - 1, dir = "N")
}
if (cy < maze_height - 1 && !visited[cx + 1, cy + 2]) {
neighbors[[length(neighbors) + 1]] <- list(x = cx, y = cy + 1, dir = "S")
}
if (length(neighbors) > 0) {
pick <- neighbors[[sample.int(length(neighbors), 1)]]
nx <- pick$x
ny <- pick$y
if (pick$dir == "E") east_open[cx + 1, cy + 1] <- TRUE
if (pick$dir == "W") east_open[nx + 1, ny + 1] <- TRUE
if (pick$dir == "S") south_open[cx + 1, cy + 1] <- TRUE
if (pick$dir == "N") south_open[nx + 1, ny + 1] <- TRUE
visited[nx + 1, ny + 1] <- TRUE
stack[[length(stack) + 1]] <- list(x = nx, y = ny)
} else {
stack[[length(stack)]] <- NULL
}
}
# --- Wall segments --------------------------------------------------------
# Row 0 sits at the top of the print, so its y-coordinate is the tallest.
vertical_walls <- expand.grid(col = 0:(maze_width - 2), row = 0:(maze_height - 1)) |>
filter(!east_open[cbind(col + 1, row + 1)]) |>
transmute(x = col + 1, xend = col + 1, y = maze_height - row - 1, yend = maze_height - row)
horizontal_walls <- expand.grid(col = 0:(maze_width - 1), row = 0:(maze_height - 2)) |>
filter(!south_open[cbind(col + 1, row + 1)]) |>
transmute(x = col, xend = col + 1, y = maze_height - row - 1, yend = maze_height - row - 1)
# Outer border, with a one-cell gap for the entrance (top-left) and exit
# (bottom-right) so the puzzle can be entered and exited with a pen.
border_walls <- tibble::tibble(
x = c(1, 0, 0, maze_width),
xend = c(maze_width, maze_width - 1, 0, maze_width),
y = c(maze_height, 0, 0, 0),
yend = c(maze_height, 0, maze_height, maze_height)
)
walls <- bind_rows(vertical_walls, horizontal_walls, border_walls)
# --- Start / goal markers --------------------------------------------------
markers <- tibble::tibble(
label = c("S", "G"),
x = c(0.5, maze_width - 0.5),
y = c(maze_height - 0.5, 0.5),
color = c(IMPRINT_PALETTE[1], IMPRINT_PALETTE[2])
)
# --- Plot --------------------------------------------------------------
title_text <- "maze-printable · r · ggplot2 · anyplot.ai"
subtitle_text <- sprintf(
"%d × %d grid · exactly one path from start to goal",
maze_width, maze_height
)
p <- ggplot() +
geom_segment(
data = walls, aes(x = x, xend = xend, y = y, yend = yend),
color = INK, linewidth = 1.3, lineend = "square", linejoin = "mitre"
) +
geom_point(
data = markers, aes(x = x, y = y, color = color),
size = 9, show.legend = FALSE
) +
geom_text(
data = markers, aes(x = x, y = y, label = label),
color = PAGE_BG, size = 4.2, fontface = "bold"
) +
scale_color_identity() +
coord_fixed(
xlim = c(-0.5, maze_width + 0.5),
ylim = c(-0.5, maze_height + 0.5),
expand = FALSE
) +
labs(title = title_text, subtitle = subtitle_text) +
theme_void(base_size = 8) +
theme(
plot.background = element_rect(fill = PAGE_BG, color = PAGE_BG),
panel.background = element_rect(fill = PAGE_BG, color = NA),
plot.title = element_text(color = INK, size = 12, hjust = 0.5, margin = margin(b = 6)),
plot.subtitle = element_text(color = INK_MUTED, size = 8, hjust = 0.5, margin = margin(b = 10)),
plot.margin = margin(t = 20, r = 20, b = 20, l = 20)
)
# --- Save --------------------------------------------------------------
ggsave(
filename = sprintf("plot-%s.png", THEME),
plot = p,
device = ragg::agg_png,
width = 6,
height = 6,
units = "in",
dpi = 400
)
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/maze-printable/ggplot2/code. Any spec id and library id listed in llms-full.txt fit the same URL shape; every URL below is complete and callable.
{
"spec_id": "maze-printable",
"language": "r",
"library": "ggplot2",
"page": "https://anyplot.ai/maze-printable/r/ggplot2",
"hub": "https://anyplot.ai/maze-printable",
"code_json": "https://api.anyplot.ai/specs/maze-printable/ggplot2/code",
"spec_json": "https://api.anyplot.ai/specs/maze-printable",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/maze-printable/r/ggplot2/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/maze-printable/r/ggplot2/plot-dark.png",
"quality_score": 90.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of Printable Maze Puzzle on anyplot.ai.