estimateTime

function formatTime(seconds)
    local hours,minutes = 0,0
    if seconds > 60 then
        minutes = math.floor(seconds/60)
        seconds = seconds%60
    end
    if minutes > 60 then
        hours = math.floor(minutes/60)
        minutes = minutes%60
    end
    if hours == 0 then
        if minutes == 0 then
            return tostring(seconds).." seconds"
        else
            return tostring(minutes).." minutes "..tostring(seconds).." seconds"
        end
    else
        if minutes == 0 then
            return tostring(hours).." hours "..tostring(seconds).." seconds"
        else
            return tostring(hours).." hours "..tostring(minutes).." minutes "..tostring(seconds).." seconds"
        end
    end
end

local function getCost(x1,y1,z1,x2,y2,z2)
    local deltax,deltay,deltaz = math.abs(x2-x1),math.abs(y2-y1),math.abs(z2-z1)
    local turnCost = 1
    if deltay == 0 or deltaz == 0 then
        turnCost = 0
    end
    local timeCost = deltax + deltay + deltaz + turnCost
    local fuelCost = deltax + deltay + deltaz
    return timeCost,fuelCost
end

function estimate(nObjective,instructions,x,y,z)
    assert(x,y,z)
    local fuelCost = 0
    local timeCost = 0
    --time to get from x,y,z to instructions[nObjective]
    local x0,y0,z0 = unpack(instructions[nObjective])
    local addTime0,addFuel0 = getCost(x,y,z,x0,y0,z0)
    fuelCost = addFuel0 + fuelCost
    timeCost = addTime0 + timeCost + 1

    for n = nObjective,#instructions-1 do
        --time to get from instructions[nObjective] to instructions[nObjective+1]
        local x1,y1,z1 = unpack(instructions[n],1,3)
        local x2,y2,z2 = unpack(instructions[n+1],1,3)
        local addTime,addFuel = getCost(x1,y1,z1,x2,y2,z2)
        local placeCost = 1
        fuelCost = fuelCost + addFuel
        timeCost = timeCost + addTime + placeCost
    end
    return fuelCost,timeCost*0.4
end

--local fuel,time = time_estimate(1,instructions,0,0,0)
--print(fuel," ",formatTime(time))