vituscze

import Data.Function

class Queue q where
    emptyQueue :: q a
    isEmpty :: q a -> Bool
    enqueue :: a -> q a -> q a
    dequeue :: q a -> (a, q a)

data SQueue a = SQ [a] [a]

vituscze

data Tree = Nil | Node Tree Int Tree deriving (Eq, Ord, Show)

allBalanced :: Int -> [Tree]
allBalanced = go 1
  where
    go from to
        | from > to = [Nil]
        | otherwise = [Node l x r | x <- [h .. h + m], l <- go from (x - 1), r <- go (x + 1) to]
      where
        (h, m) = (from + to) `divMod` 2

vituscze

import Data.List

is_equiv :: (a -> a -> Bool) -> [a] -> Bool
is_equiv (~=) set = refl && sym && trans
  where
    infix 1 ==>
    x ==> y = not x || y

    every c = all c set

vituscze

factors_ :: Int -> Int -> [Int]
factors_ p k =
    if k * k > p
    then [p]
    else if p `mod` k == 0
        then k:factors_ (p `div` k) k
        else factors_ p (k + 1)

factors :: Int -> [Int]
factors p = factors_ p 2

vituscze

mark_enter(X, enter(X)).

dfs(_, [], Visited, Visited, Time, Time).
dfs(G, [exit(V)|Vs], Visited, FinalVisited, Time, FinalTime) :-
    member(V/_/Time, Visited), NewTime is Time + 1,
    dfs(G, Vs, Visited, FinalVisited, NewTime, FinalTime).
dfs(G, [enter(V)|Vs], Visited, FinalVisited, Time, FinalTime) :-
    ( member(V/_/_, Visited) -> dfs(G, Vs, Visited, FinalVisited, Time, FinalTime)
    ; member(V-Neigh, G), maplist(mark_enter, Neigh, NeighEnter),
      NewTime is Time + 1,

vituscze

maptree(_, nil).
maptree(P, b(L, X, R)) :-
    call(P, X), maptree(P, L), maptree(P, R).

size(nil, 0, -1).
size(b(L, _, R), S, H) :-
    SP is S - 1, between(0, SP, SL), SR is S - SL - 1,
    HP is H - 1, (HL = HP, between(-1, HP, HR); between(-1, HP, HL), HR = HP, HL \= HR),
    size(L, SL, HL),
    size(R, SR, HR).

vituscze

cone([o,o,o], 0).
cone(R, 1) :- select(x, R, [o,o]).
cone(R, 2) :- select(o, R, [x,x]).
cone([x,x,x], 3).

match([_,_], []).
match([A,B,C|R], [M|RM]) :- cone([A,B,C],M), match([B,C|R], RM).

miny(Pocty, Miny) :- same_length(Pocty, Miny), append([[o],Miny,[o]], MinyLong), match(MinyLong, Pocty).

vituscze

sublist(L, M) :-
    M = [_|_],
    append(_, Suffix, L),
    append(M, _, Suffix).

subseq([], []).
subseq([X|L], [X|M]) :- subseq(L, M).
subseq([_|L], M) :- subseq(L, M).

disjoint([], [], []).

vituscze

% recodex: revize

person(O) :- member(O, [david, thomas, emma, stella]).

across(david, thomas).
across(thomas, david).
across(emma, stella).
across(stella, emma).

distinct(A, B, C, D) :-

vituscze

natural(0).
natural(s(N)) :- natural(N).

smaller(0, s(_)).
smaller(s(M), s(N)) :- smaller(M, N).

% Predikat postupne generuje dvojice prirozenych cisel X, Y tak,
% ze X < Y.
gen_smaller(X, Y) :- natural(Y), smaller(X, Y).