A lost, blind kangaroo (Skippy) starts in position (0,0) of a grid, and is trying to get home, which happens to be at cell (dimension - 1, dimension - 1).
His strategy is to take random hops either Direction::NORTH, Direction::SOUTH, Direction::EAST or Direction::WEST (with equal probability), without exiting the grid of course.
The question is, will this strategy get Skippy home, or will he hop around the grid forever?
More at: Part I: Basic Simulation
- Java 10+
- Ruby 2.7+
- Run tests:
mvn test - Run the program:
mvn exec:java "-Dexec.mainClass=org.my_projects.skippy.Main"
- Install dependencies:
./bin/setup - Run tests:
bundle exec rake - Run the program:
ruby ./bin/console
Enter dimension of the grid (>=1):
100
Oops, hit the boundary: (-1, 0)
Oops, hit the boundary: (-1, 0)
Hopped to: (1, 0)
Hopped to: (1, 1)
...
Hopped to: (97, 99)
Oops, hit the boundary: (97, 100)
Hopped to: (98, 99)
Hopped to: (98, 98)
Hopped to: (98, 99)
Oops, hit the boundary: (98, 100)
Hopped to: (99, 99)
Finished in 119044 hops!
Die statistics:
Total throws: 119044
North: 24.9% South: 25.1% East: 25.1% West: 25.0%
Gridis a container with items on it. It provides methods for updating and retrieving item locations (place_item,move_item,get_item_location) and makes it impossible for items to exit the grid (OutOfBoundsError)- Skippy is an instance of
Kangaroo. He is responsible for finding his way back to home (find_home).Kangarooencapsulates this strategy: kangaroos roll the die and hop around the grid, instead of someone else rolling the die and making them hop. Dieis a Singleton: we only need one die and one type of die in this exercise. It records its history and prints its own statistics.- Classes are grouped into 3 modules:
Skippy::Direction,Skippy::GridandSkippy::Kangaroo - The outputs of this program are because of Skippy chortling or the die printing its statistics.
