Part 1



In [1]:

    
test = [
    "0: 3",
    "1: 2",
    "4: 4",
    "6: 4"
]









    Out[1]:





4-element Array{String,1}:
 "0: 3"
 "1: 2"
 "4: 4"
 "6: 4"



In [2]:

    
function parse_input(values)
    result = Dict()
    for v in values
        depth, range = match(r"([0-9]+): ([0-9]+)", v).captures
        result[parse(Int32, depth)] = parse(Int32, range)
    end
    result
end









    Out[2]:





parse_input (generic function with 1 method)



In [3]:

    
firewall = parse_input(test)









    Out[3]:





Dict{Any,Any} with 4 entries:
  0 => 3
  4 => 4
  6 => 4
  1 => 2



In [4]:

    
function compute_severity(firewall, delay)    
    severity = 0
    max_time = maximum(keys(firewall)) + delay
    p = -delay
    for t = 0:max_time
        if haskey(firewall, p) && t % (2*firewall[p] - 2)==0
            severity += t*firewall[p]
        end        
        p += 1
    end
    severity
end









    Out[4]:





compute_severity (generic function with 1 method)



In [5]:

    
compute_severity(parse_input(test), 0)









    Out[5]:





24



In [6]:

    
open("inputs/day13.txt") do fd
    lines = readlines(fd)
    compute_severity(parse_input(lines), 0)
end









    Out[6]:





1704

Part 2



In [7]:

    
function is_caught(firewall, delay)    
    max_time = maximum(keys(firewall)) + delay
    p = 0
    for t = delay:max_time
        if haskey(firewall, p) && t % (2*firewall[p] - 2)==0
            return true
        end        
        p += 1
    end
    return false
end

function no_caught(firewall)    
    w = 0
    while is_caught(firewall, w)
        if w%10000000 == 0
            println(w)
        end
        w += 1
    end    
    w
end









    Out[7]:





no_caught (generic function with 1 method)



In [8]:

    
compute_severity(parse_input(test), 10)









    Out[8]:





0



In [9]:

    
no_caught(parse_input(test))



In [13]:

    
open("inputs/day13.txt") do fd
    lines = readlines(fd)
    @time no_caught(parse_input(lines))
end









    



0
  7.560550 seconds (60.41 M allocations: 1.141 GiB, 0.79% gc time)






    Out[13]:





3970918



In [ ]: