Count occurrences of a substring: Difference between revisions

=={{header|OCaml}}==

<lang ocaml>let count_substring str sub =

let sub_len = String.length sub in

let len_diff = (String.length str) - sub_len

and reg = Str.regexp_string sub in

let rec aux i n =

if i > len_diff then n else

try

let pos = Str.search_forward reg str i in

aux (pos + sub_len) (succ n)

with Not_found -> n

in

aux 0 0

let () =

Printf.printf "count 1: %d\n" (count_substring "the three truth" "th");

Printf.printf "count 2: %d\n" (count_substring "ababababab" "abab");

;;</lang>