ruby - Regular expression: if three letters are included -

i've got number of word: hello, poison, world, search, echo ... , i've got letters e, h, o need find words includes letters. search, echo e, h, o

i can search way:

words = %w[hello poison world search echo] matched = words.select |w|   %w[e,h,o].all?{ |l| w =~ /#{l}/ } end 

the problem if letters o, o, o, or l, b, l search return true words open or boil, need search words includes 3 of o or 2 of l , 1 b

upd:

leters = "abc" words.select{ |w| w.count(letters) >= 3 } 

upd 2

bad solution, example:

"lllllll".count("lua") #=> 5 

are sure want regexp? strings support counting values in them, use feature. this:

words = ["pool", "tool", "troll", "lot"] letters = "olo"  #find how many of each letter need counts = {} letters.each { |v| counts[v] = letters.count(v) }  #see if given work matches counts # accumulated above res = words.select |w|   counts.keys.inject(true) |match, letter|        match && (w.count(letter) == counts[letter])   end end