18 lines
515 B
OCaml
18 lines
515 B
OCaml
open Base
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type nucleotide = A | C | G | T
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let toint = function
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| A -> 0
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| C -> 1
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| G -> 2
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| T -> 3
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let hamming_distance a b = match (a, b) with
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| [], [] -> Ok 0
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| [], _ -> Error "left strand must not be empty"
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| _, [] -> Error "right strand must not be empty"
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| l1, l2 -> match List.zip l1 l2 with
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| Ok res -> Ok (List.filter ~f:(fun (x, y) -> (toint x) <> (toint y)) res |> List.length)
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| Unequal_lengths -> Error "left and right strands must be of equal length"
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