亂打亂撞 [乱－乱－]

Jyutping lyun6 daa2 lyun6 zong6
Pinyin luàn dǎ luàn zhuàng

Definitions (粵典–words.hk)
  1. 動詞
    唔​知道​實​際​嘅​竅​門​，​靠​運氣​做到
    to score a lucky hit, to reach one's goal without having a clear idea how one got there.

亂打亂撞 [乱－乱－]

Jyutping lyun6 daa2 lyun6 zong6
Pinyin luàn dǎ3luan zhuàng

Definitions (CC-CANTO)
  1. to act blindly without thinking; to blindly stumble one's way through; to go about blindly and haphazardly [written and colloquial]