class Array def bsearch(v) l = -1 r = size while r - l > 1 m = (l + r) / 2 self[m] >= v ? r = m : l = m end self[r] == v ? self[r] : nil end def bsearch_index(v) l = -1 r = size while r - l > 1 m = (l + r) / 2 self[m] < v ? l = m : r = m e…