giles
3759aad7a6
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Failing after 22s
canonical builds a sorted-by-frequency string representation:
let canonical s =
let chars = Array.make 26 0 in
for i = 0 to String.length s - 1 do
let k = Char.code s.[i] - Char.code 'a' in
if k >= 0 && k < 26 then chars.(k) <- chars.(k) + 1
done;
expand into a-z order via a Buffer
For 'eat', 'tea', 'ate' -> all canonicalise to 'aet'. For 'tan',
'nat' -> 'ant'. For 'bat' -> 'abt'.
group_anagrams folds the input, accumulating per-key string lists;
final answer is Hashtbl.length (number of distinct groups):
['eat'; 'tea'; 'tan'; 'ate'; 'nat'; 'bat'] -> 3 groups
99 baseline programs total.
30 lines
736 B
OCaml
30 lines
736 B
OCaml
let canonical s =
|
|
let chars = Array.make 26 0 in
|
|
for i = 0 to String.length s - 1 do
|
|
let k = Char.code s.[i] - Char.code 'a' in
|
|
if k >= 0 && k < 26 then chars.(k) <- chars.(k) + 1
|
|
done;
|
|
let buf = Buffer.create 26 in
|
|
for i = 0 to 25 do
|
|
for _ = 1 to chars.(i) do
|
|
Buffer.add_string buf (String.make 1 (Char.chr (i + Char.code 'a')))
|
|
done
|
|
done;
|
|
Buffer.contents buf
|
|
|
|
let group_anagrams xs =
|
|
let h = Hashtbl.create 8 in
|
|
List.iter (fun s ->
|
|
let k = canonical s in
|
|
let cur = match Hashtbl.find_opt h k with
|
|
| Some xs -> xs
|
|
| None -> []
|
|
in
|
|
Hashtbl.replace h k (s :: cur)
|
|
) xs;
|
|
Hashtbl.length h
|
|
|
|
;;
|
|
|
|
group_anagrams ["eat"; "tea"; "tan"; "ate"; "nat"; "bat"]
|