README.md

retro-route-puzzle

A-Maze-ingly Retro Route Puzzle

This is a JSON variant of the problem described by this blog post.

Problem

Write a program that will output a valid route one could follow to collect all specified items within a map. The map is a json description of set of rooms with allowed path and contained object.

Exercise starts with an input of:

• json reppresentation of map
• starting room
• list of object to collect

Room type allowed fields

  id: Integer
  name: String
  north: Integer //referring to a connected room
  south: Integer //referring to a connected room
  west: Integer //referring to a connected room
  east: Integer //referring to a connected room
  objects: List //of Objects
  
Object type allowed fields
  name: String //Object Name

Example

Map

{
  "rooms": [
    { "id": 1, "name": "Hallway", "north": 2, "objects": [] },
    { "id": 2, "name": "Dining Room", "south": 1, "west": 3, "east": 4, "objects": [] },
    { "id": 3, "name": "Kitchen","east":2, "objects": [ { "name": "Knife" } ] },
    { "id": 4, "name": "Sun Room","west":2, "objects": [ { "name": "Potted Plant" } ] }
  ]
}

Input

Start Room ID = 2
Objects To Collect = Knife, Potted Plant

Output

ID	Room	Object collected
0	Dining Room	None
1	Hallway	None
2	Dining Room	None
3	Kitchen	Knife
2	Dining Room	None
4	Sun Room	Potted Plant

Additional Goals

• TDD approach.
• Build a Docker container with runnable code inside so that we can mount a volume in it and test on different maps.

Build instructions

To build a runnable jar:

mvn clean package

To build a runnable docker image:

mvn clean package docker:build

Usage

Example:

java -jar target/retro-route-puzzle-<version>.jar -m map.json -r 2 -i "Knife" "Potted Plant"

Example using Docker:

docker run -v `pwd`:`pwd` -w `pwd` retro-route-puzzle -m map.json -r 2 -i "Knife" "Potted Plant"

Implementation notes

The search algorithm is a greedy multi step graph visit, where each step uses Breadth First Search or Depth First Search. In either case the complexity is O(R) where R is the number of rooms, but in general BFS should result in shorter routes.