Collins Chinese Dictionary Plus (3rd edition), 2011:
一了百了 yī liǎo bǎi liǎo find a single solution
- 事情错(錯)综(綜)复(複)杂(雜)，很难(難)找到一个(個)一了百了的解决(決)办(辦)法。 Shìqing cuòzōng fùzá，hěn nán zhǎodào yī gè yī liǎo bǎi liǎo de jiějué bànfǎ. Matters are very complex. It's very difficult to find a single solution to all problems.