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#!/usr/bin/env ruby
def turn_left(vector)
return case vector
when [1, 0]
[0, 1]
when [0, 1]
[-1, 0]
when [-1, 0]
[0, -1]
when [0, -1]
[1, 0]
end
end
def turn_right(vector)
return case vector
when [1, 0]
[0, -1]
when [0, -1]
[-1, 0]
when [-1, 0]
[0, 1]
when [0, 1]
[1, 0]
end
end
def turn(map, vector, row, col)
lvec = turn_left(vector)
rvec = turn_right(vector)
lrow = row + lvec[0]
lcol = col + lvec[1]
rrow = row + rvec[0]
rcol = col + rvec[1]
if map[lrow][lcol] == ' ' then
return rvec
else
return lvec
end
end
input = $stdin.readlines.map(&:chomp).map(&:chars).map(&:to_a)
row = 0
col = input[0].index('|')
vec = [1, 0]
steps = 0
loop do
row += vec[0]
col += vec[1]
steps += 1
this = input[row][col]
if this == ' ' then
break
elsif this == '+' then
vec = turn(input, vec, row, col)
end
end
puts steps
|
