Round_Robin_Variant

local input = io.read("*a")
local tasks = {}
local stack = {}
local processes = {}
local processors = {}
local n
local processing = 0

for line in input:gmatch("[^\n]+") do
    n = tonumber(line)
    if not n then
        local arrow_location = line:find("->")
        local first_node = line:sub(1, arrow_location):match("%a+")
        local second_node = line:sub(arrow_location):match("%a+")
        tasks[first_node.."->"..second_node] = tonumber(line:match("%d+"))
    end
end

n = n or 1
for i = 1, n do
    processors["P"..i] = false
end

for task in pairs(tasks) do
    if task:match("START") then
        processes[task] = true
        table.insert(stack, task)
    end
end

while processing < n do
    processing = 0
    for i = 1, n do
        local processor = "P"..i
        local last_task = processors[processor]
        if last_task then
            tasks[last_task] = tasks[last_task] - 1
            if tasks[last_task]  > 0 then
                table.insert(stack, 1, last_task)
            else
                for task in pairs(tasks) do
                    if not processes[task] then
                        if last_task:reverse():match("%a+"):reverse() == task:match("%a+") then
                            local can_add = true
                            for other_task, time in pairs(tasks) do
                                if other_task:reverse():match("%a+"):reverse() == task:match("%a+") and time > 0 then
                                    can_add = false
                                end
                            end
                            if can_add then
                                processes[task] = true
                                table.insert(stack, task)
                            end
                        end
                    end
                end
            end
            processors[processor] = false
        end
        if #stack > 0 then
            local task = table.remove(stack)
            local second_node = task:reverse():match("%a+"):reverse()
            io.write(processor, " processing task: ", second_node, "\n")
            processors[processor] = task
        else
            processing = processing + 1
            processors[processor] = false
            io.write(processor, ": no task available to process at this time.", "\n")
        end
    end
end
io.write("\n", "Processing complete!", "\n\n")