tā / cǎi / yòng / le / zì / dǐ / xiàng / shàng / de / cè / lüè / lái / jiě / jué / zhè / gè / fù / zá / de / wèn / tí

他采用了自底向上的策略来解决这个复杂的问题。

He adopted a bottom-up strategy to solve this complex problem.