As the bilingual vocabulary V consists of the pinyin and Chinese word pair of all the words that ever appeared, it is natural to use a prefix maximum matching algorithm to obtain a sorted list of relevant candidate translations D(x) = [Ch 1 , Ch 2 , ...] for the source pinyin.
we generate a target vocabulary V s for a sentence x = (P y 1 , P y 2 , ...) by merging all the candidates of all pinyin.