lean4-htt/tests/bench/unionfind.lean

126 lines
4.3 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

def StateT' (m : Type → Type) (σ : Type) (α : Type) := σ → m (α × σ)
namespace StateT'
variables {m : Type → Type} [Monad m] {σ : Type} {α β : Type}
@[inline] protected def pure (a : α) : StateT' m σ α := fun s => pure (a, s)
@[inline] protected def bind (x : StateT' m σ α) (f : α → StateT' m σ β) : StateT' m σ β := fun s => do (a, s') ← x s; f a s'
@[inline] def read : StateT' m σ σ := fun s => pure (s, s)
@[inline] def write (s' : σ) : StateT' m σ Unit := fun s => pure ((), s')
@[inline] def updt (f : σσ) : StateT' m σ Unit := fun s => pure ((), f s)
instance : Monad (StateT' m σ) :=
{pure := @StateT'.pure _ _ _, bind := @StateT'.bind _ _ _}
end StateT'
def ExceptT' (m : Type → Type) (ε : Type) (α : Type) := m (Except ε α)
namespace ExceptT'
variables {m : Type → Type} [Monad m] {ε : Type} {α β : Type}
@[inline] protected def pure (a : α) : ExceptT' m ε α := (pure (Except.ok a) : m (Except ε α))
@[inline] protected def bind (x : ExceptT' m ε α) (f : α → ExceptT' m ε β) : ExceptT' m ε β :=
(do { v ← x; match v with
| Except.error e => pure (Except.error e)
| Except.ok a => f a } : m (Except ε β))
@[inline] def error (e : ε) : ExceptT' m ε α := (pure (Except.error e) : m (Except ε α))
@[inline] def lift (x : m α) : ExceptT' m ε α := (do {a ← x; pure (Except.ok a) } : m (Except ε α))
instance : Monad (ExceptT' m ε) :=
{pure := @ExceptT'.pure _ _ _, bind := @ExceptT'.bind _ _ _}
end ExceptT'
abbrev Node := Nat
structure nodeData :=
(find : Node) (rank : Nat := 0)
abbrev ufData := Array nodeData
abbrev M (α : Type) := ExceptT' (StateT' Id ufData) String α
@[inline] def read : M ufData := ExceptT'.lift StateT'.read
@[inline] def write (s : ufData) : M Unit := ExceptT'.lift (StateT'.write s)
@[inline] def updt (f : ufData → ufData) : M Unit := ExceptT'.lift (StateT'.updt f)
@[inline] def error {α : Type} (e : String) : M α := ExceptT'.error e
def run {α : Type} (x : M α) (s : ufData := ∅) : Except String α × ufData :=
x s
def capacity : M Nat :=
do d ← read; pure d.size
def findEntryAux : Nat → Node → M nodeData
| 0, n => error "out of fuel"
| i+1, n =>
do s ← read;
if h : n < s.size then
do { let e := s.get ⟨n, h⟩;
if e.find = n then pure e
else do e₁ ← findEntryAux i e.find;
updt (fun s => s.set! n e₁);
pure e₁ }
else error "invalid Node"
def findEntry (n : Node) : M nodeData :=
do c ← capacity;
findEntryAux c n
def find (n : Node) : M Node :=
do e ← findEntry n; pure e.find
def mk : M Node :=
do n ← capacity;
updt $ fun s => s.push {find := n, rank := 1};
pure n
def union (n₁ n₂ : Node) : M Unit :=
do r₁ ← findEntry n₁;
r₂ ← findEntry n₂;
if r₁.find = r₂.find then pure ()
else updt $ fun s =>
if r₁.rank < r₂.rank then s.set! r₁.find { find := r₂.find }
else if r₁.rank = r₂.rank then
let s₁ := s.set! r₁.find { find := r₂.find };
s₁.set! r₂.find { rank := r₂.rank + 1, .. r₂}
else s.set! r₂.find { find := r₁.find }
def mkNodes : Nat → M Unit
| 0 => pure ()
| n+1 => mk *> mkNodes n
def checkEq (n₁ n₂ : Node) : M Unit :=
do r₁ ← find n₁; r₂ ← find n₂;
unless (r₁ = r₂) $ error "nodes are not equal"
def mergePackAux : Nat → Nat → Nat → M Unit
| 0, _, _ => pure ()
| i+1, n, d =>
do c ← capacity;
if (n+d) < c
then union n (n+d) *> mergePackAux i (n+1) d
else pure ()
def mergePack (d : Nat) : M Unit :=
do c ← capacity; mergePackAux c 0 d
def numEqsAux : Nat → Node → Nat → M Nat
| 0, _, r => pure r
| i+1, n, r =>
do c ← capacity;
if n < c
then do { n₁ ← find n; numEqsAux i (n+1) (if n = n₁ then r else r+1) }
else pure r
def numEqs : M Nat :=
do c ← capacity;
numEqsAux c 0 0
def test (n : Nat) : M Nat :=
if n < 2 then error "input must be greater than 1"
else do
mkNodes n;
mergePack 50000;
mergePack 10000;
mergePack 5000;
mergePack 1000;
numEqs
def main (xs : List String) : IO UInt32 :=
let n := xs.head!.toNat;
match run (test n) with
| (Except.ok v, s) => IO.println ("ok " ++ toString v) *> pure 0
| (Except.error e, s) => IO.println ("Error : " ++ e) *> pure 1