14 lines
299 B
OCaml
14 lines
299 B
OCaml
let rec pow a = function
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| 0 -> 1
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| 1 -> a
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| n ->
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let b = pow a (n / 2) in
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b * b * (if n mod 2 = 0 then 1 else a)
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let rec powmod a d = function
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| 0 -> 1
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| 1 -> a mod d
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| n ->
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let b = (powmod a d (n / 2)) mod d in
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(((b * b) mod d) * (if n mod 2 = 0 then 1 else a)) mod d
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