adventofcode

adventofcode.jl

function santa(current, next)
         if next == '^' current[1] += 1 
         elseif next == 'v' current[1] -= 1
         elseif next == '<' current[2] += 1 
         elseif next == '>' current[2] -= 1 
         else println("not known:", next) end
       current
       end

#assign variable grid = input from http://adventofcode.com/day/3/input

### This solution doesn't work
x = Set{ Array{Int64,2}}()
start = [0 0]
push!(x, start)

for i in grid
	start = santa(start, i)
    push!(x, start)
end
println(length(x))

### This solution works!
x = Set{ ASCIIString }()
start = [0 0]
push!(x, string(start))
for i in grid
    start = santa(start, i)
    push!(x, string(start))
end
println(length(x))

If you rewrite the solution to use tuples, it works too:

### This solution works too!
function santa(current, next)
    next == '^' && return (current[1] + 1, current[2])
    next == 'v' && return (current[1] - 1, current[2])
    next == '<' && return (current[1], current[2] + 1)
    next == '>' && return (current[1], current[2] - 1)
    println("not known: ", next)
end

x = Set{Tuple{Int64,Int64}}()
start = (0,0)
push!(x, start)

for i in grid
    start = santa(start, i)
    push!(x, start)
end
println(length(x))