#make_comb([1,3,4],2) → [1,3],[1,4],[3,4] #make_comb([1,2,3,4],2)→[1,2],[1,3],[1,4]・・ #make_commb([1,2,3,4,5],3)→[1,2,3]・・[2,4,5] def make_comb(array,num) # [2,3] → [[2][3]] # result ||= [] if num == 1 array.each do |elem| result << [e…