0 a search that is completely unsuccessful and a waste of time because the person or thing being searched for does not exist or is somewhere else -- 白费力气的搜寻;徒劳之举
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
再长的路,一步步也能走完,再短的路,不迈开双脚也无法到达。