spiral

Your goal is to traverse a spiral from one of the maze corners to its center. There are no items to collect this time.

Problem statement

Maze format

• let n be a positive integer
• you are given a (4n+2)x(4n+1) grid
  • there are solid walls on all of its 4 borders (so there is a solid left,right,bottom,top wall line)
• the origin (1,1) is located at the top left corner of the maze (the intersection of the top and left border)
• the robot starts at the top-right-most empty cell (position (2,4n))
• right underneath the robot, there starts a spiral that whirls towards the center and makes a left turn two blocks before a wall

Objective

• just get to the end by any means

Examples

You may find all of the inputs and outputs in the Examples/spiral directory. See the robot's progress while solving these problems by e.g. running

./main.lua test -p Examples/spiral/spiral_n1.in Examples/spiral/spiral_n1.out

or just

./main.lua test -p Examples/spiral/spiral_n2.{in,out}

if your shell supports it.

Example 1

Example input (n=1) (Examples/spiral/spiral_n1.in)

spiral
6 5
# # # # #
# . . S #
# . # # #
# . # E #
# . . . #
# # # # #

Example final form

# # # # #
# . . S #
# . # # #
# . # n #
# . . . #
# # # # #

Example output (Examples/spiral/spiral_n1.out)

turnleft
movetowall
turnleft
movetowall
turnleft
movetowall
turnleft
movetowall

Example 2

Example input (n=4) (Examples/spiral/spiral_n4.in)

spiral
18 17
# # # # # # # # # # # # # # # # #
# . . . . . . . . . . . . . . S #
# . # # # # # # # # # # # # # # #
# . # . . . . . . . . . . . . . #
# . # . # # # # # # # # # # # . #
# . # . # . . . . . . . . . # . #
# . # . # . # # # # # # # . # . #
# . # . # . # . . . . . # . # . #
# . # . # . # . # # # . # . # . #
# . # . # . # . # E # . # . # . #
# . # . # . # . . . # . # . # . #
# . # . # . # # # # # . # . # . #
# . # . # . . . . . . . # . # . #
# . # . # # # # # # # # # . # . #
# . # . . . . . . . . . . . # . #
# . # # # # # # # # # # # # # . #
# . . . . . . . . . . . . . . . #
# # # # # # # # # # # # # # # # #

Example final form

# # # # # # # # # # # # # # # # #
# . . . . . . . . . . . . . . S #
# . # # # # # # # # # # # # # # #
# . # . . . . . . . . . . . . . #
# . # . # # # # # # # # # # # . #
# . # . # . . . . . . . . . # . #
# . # . # . # # # # # # # . # . #
# . # . # . # . . . . . # . # . #
# . # . # . # . # # # . # . # . #
# . # . # . # . # nE # . # . # . #
# . # . # . # . . . # . # . # . #
# . # . # . # # # # # . # . # . #
# . # . # . . . . . . . # . # . #
# . # . # # # # # # # # # . # . #
# . # . . . . . . . . . . . # . #
# . # # # # # # # # # # # # # . #
# . . . . . . . . . . . . . . . #
# # # # # # # # # # # # # # # # #