The vectorless approaches, on the other hand, aim to compute an upper bound on the worst-case drop in an efficient manner.
ðə vˈɛktɚləs ɐpɹˈoʊtʃᵻz, ɔnðɪ ˈʌðɚ hˈænd, ˈeɪm tə kəmpjˈuːt ɐn ˌʌpɚ bˈaʊnd ɔnðə wˈɜːstkˈeɪs dɹˈɑːp ɪn ɐn ɪfˈɪʃənt mˈænɚ.