Test Problem

urinal_etiquette.rb

# Rule 1: Farthest from the door
# Rule 2: Dont stand next to occupied
# Rule 3: Dont stand between 2 dudes
# Except: If line => Ignore 2 & 3
# Except: If 2 or 3 is broken, ignore them
def which_stall(stalls, line)
    if line || rules_broken?(stalls)
        return furthest_empty(stalls)
    end

    find_by_rules(stalls) 
end

def find_by_rules(stalls)
    available = []

    stalls.each_with_index do |obj, i|
        if not stalls[i] and not stalls[i + 1]
            available << i
        end
    end

    # print available, "\n"
    # print available.count, "\n"

    if 0 != available.count
        return available.last
    end
    return -1
end

def furthest_empty(stalls)
    # index of the last element that's false
    if stalls.any? { |obj| obj == false }
        return stalls.rindex(false)
    end
    return -1
end

def rules_broken?(stalls)
    # validate rules 1 - 3 are true
    # rule 1
    if not stalls.last and stalls[0..-1].any? { |obj| obj == true }
        return true
    end

    # rule 2 and rule 3
    0.upto(stalls.length - 2) do |i|
        if stalls[i] and stalls[i+1]
            return true
        end
    end

    return false
end

urinal_etiquette_test.rb

print 4, ' = ', which_stall([true, false, true, false, false], false), "\n"
print -1, ' = ', which_stall([true, false, true, false, true], false), "\n"
print -1, ' = ', which_stall([true, true, true, true, true], false), "\n"
print 3, ' = ', which_stall([false, false, true, false, true], true), "\n"

print 0, ' = ', which_stall([false, false, true, false, true], false), "\n"
print 2, ' = ', which_stall([false, false, false, false, true], false), "\n"
print 0, ' = ', which_stall([false, true, true, true], false), "\n"
print 0, ' = ', which_stall([false, true, false, true], false), "\n"