Mix.install([
{:jason, "~> 1.4"},
{:kino, "~> 0.9", override: true},
{:youtube, github: "brooklinjazz/youtube"},
{:hidden_cell, github: "brooklinjazz/hidden_cell"}
])
In this exercise, you're going to navigate a maze game.
Each maze is a deeply nested map
.
If you navigate successfully, your answer will return "Exit!"
We've created a map that represents the following maze. Each cardinal direction (north, south, west, east) necessary to navigate the maze is stored as a key in the map.
Use map.key notation to access the "Exit!"
string.
Example solution
maze = %{
south: %{
west: %{
south: %{
east: %{
south: %{
east: %{
south: "Exit!"
}
}
}
}
}
}
}
maze.south.west.south.east.south.east.south
maze = %{
south: %{
west: %{
south: %{
east: %{
south: %{
east: %{
south: "Exit!"
}
}
}
}
}
}
}
Use map[key] notation to access the maze and retrieve the "Exit!"
string.
Example solution
maze = %{
"south" => %{
"east" => %{
"south" => %{
"west" => %{
"south" => %{
"west" => %{
"south" => %{
"east" => %{
"south" => "Exit!"
}
}
}
}
}
}
}
}
}
maze["south"]["east"]["south"]["west"]["south"]["west"]["south"]["east"]["south"]
maze = %{
"south" => %{
"east" => %{
"south" => %{
"west" => %{
"south" => %{
"west" => %{
"south" => %{
"east" => %{
"south" => "Exit!"
}
}
}
}
}
}
}
}
}
You have been given a treasure map (pun intended). That will lead you to "gold"
.
Use map[key] and/or map.key notation to retrieve the "gold"
value in the treasure_map
.
Example solution
treasure_map = %{
"south ten paces" => %{
10 => %{
:"east three paces" => %{
[1, 2, 3] => %{
{"turn", "right"} => %{
:dig => "gold"
}
}
}
}
}
}
treasure_map["south ten paces"][10][:"east three paces"][[1, 2, 3]][{"turn", "right"}][:dig]
treasure_map = %{
"south ten paces" => %{
10 => %{
:"east three paces" => %{
[1, 2, 3] => %{
{"turn", "right"} => %{
:dig => "gold"
}
}
}
}
}
}
Use map update syntax to create and update the original treasure_map
such that the "gold"
is now "taken"
.
Example solution
treasure_map = %{
"south ten paces" => %{
10 => %{
:"east three paces" => %{
[1, 2, 3] => %{
{"turn", "right"} => %{
:dig => "gold"
}
}
}
}
}
}
We can update the treasure map using map update syntax %{old_map | updated_key}
.
%{
treasure_map
| "south ten paces" => %{
10 => %{
:"east three paces" => %{
[1, 2, 3] => %{
{"turn", "right"} => %{:dig => "taken"}
}
}
}
}
}
You might also have found the Kernel.put_in function for updating a deeply nested map.
put_in(
treasure_map,
["south ten paces", 10, :"east three paces", [1, 2, 3], {"turn", "right"}, :dig],
"taken"
)
Enter your solution below.
treasure_map = %{
"south ten paces" => %{
10 => %{
:"east three paces" => %{
[1, 2, 3] => %{
{"turn", "right"} => %{
:dig => "gold"
}
}
}
}
}
}
Use pattern matching to bind the "Exit!"
string to an exit
variable.
maze = %{
"south" => %{
"east" => %{
"south" => %{
"west" => %{
"south" => %{
"west" => %{
"south" => %{
"east" => %{
"south" => "Exit!"
}
}
}
}
}
}
}
}
}
Generate a maze using the Online Maze Generator. It should be at least a 5 * 5 in width and height.
- Create a deeply nested map to represent your
custom_maze
. It should have an"Exit!"
value at the end. - Have a partner navigate your maze using either map[key] notation or map.key notation to retrieve the
"Exit!"
value.
Enter your solution below.
DockYard Academy now recommends you use the latest Release rather than forking or cloning our repository.
Run git status
to ensure there are no undesirable changes.
Then run the following in your command line from the curriculum
folder to commit your progress.
$ git add .
$ git commit -m "finish Mazes exercise"
$ git push
We're proud to offer our open-source curriculum free of charge for anyone to learn from at their own pace.
We also offer a paid course where you can learn from an instructor alongside a cohort of your peers. We will accept applications for the June-August 2023 cohort soon.