Write a robot simulator.
A robot factory's test facility needs a program to verify robot movements.
The robots have three possible movements:
- turn right
- turn left
- advance
Robots are placed on a hypothetical infinite grid, facing a particular direction (north, east, south, or west) at a set of {x,y} coordinates, e.g., {3,8}, with coordinates increasing to the north and east.
The robot then receives a number of instructions, at which point the testing facility verifies the robot's new position, and in which direction it is pointing.
- The letter-string "RAALAL" means:
- Turn right
- Advance twice
- Turn left
- Advance once
- Turn left yet again
- Say a robot starts at {7, 3} facing north. Then running this stream of instructions should leave it at {9, 4} facing west.
Execute the tests with:
$ mix test
In the test suites, all but the first test have been skipped.
Once you get a test passing, you can unskip the next one by
commenting out the relevant @tag :pending
with a #
symbol.
For example:
# @tag :pending
test "shouting" do
assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end
Or, you can enable all the tests by commenting out the
ExUnit.configure
line in the test suite.
# ExUnit.configure exclude: :pending, trace: true
If you're stuck on something, it may help to look at some of the available resources out there where answers might be found.
Inspired by an interview question at a famous company.
It's possible to submit an incomplete solution so you can see how others have completed the exercise.