roditelj(dragan, dusan).
roditelj(milica, dusan).
roditelj(dusan, toma).
roditelj(dusan, jovana).
roditelj(dusan, ivan).
roditelj(toma,marko).
roditelj(verica, marko).
roditelj(toma,maja).
roditelj(verica, maja).
musko(dragan).
musko(dusan).
musko(toma).
musko(marko).
musko(ivan).
zensko(jovana).
zensko(verica).
zensko(maja).
otac(X,Y):-roditelj(X,Y),musko(X).
majka(X,Y):- roditelj(X,Y),zensko(X).
brat(X,Y):-roditelj(Z,X),roditelj(Z,Y),musko(X),not(X=Y).
sestra(X,Y):-roditelj(Z,X),roditelj(Z,Y),zensko(X),not(X=Y).
tetka(X,Y):-roditelj(Z,Y),sestra(X,Z).
stric(X,Y):-roditelj(Z,Y),brat(X,Z).

%maksimum dva/tri broja
maks(X,Y,X):-X>=Y.
maks(X,Y,Y):- X<Y.
maksTri(X,Y,Z,P):-maks(X,Y,M),maks(M,Z,P).

% obrtanje broja
obrni(N,X):- obrni(N,X,0).
obrni(0,X,X).
obrni(N,X,K):- N>0, C is N mod 10, K1 is K*10+C, N1 is N // 10, obrni(N1,X,K1).

%suma od 1 do N
sumaN(N,S):- suma(N,0,S).
suma(0,S,S).
suma(N,S1,S):-N>0,SN is S1+N,N1 is N-1,suma(N1,SN,S).

% suma pranih i neparnih
sumaPN(N,SP,SN):-sumaPN(N,0,SP,0,SN).
sumaPN(0,SP,SP,SN,SN).
sumaPN(N,SP1,SP,SN1,SN):- N>0,N mod 2=:=0,SP2 is SP1+N,N1 is N-1,sumaPN(N1,SP2,SP,SN1,SN).
sumaPN(N,SP1,SP,SN1,SN):- N>0,N mod 2=\=0,SN2 is SN1+N,N1 is N-1,sumaPN(N1,SP1,SP,SN2,SN).

% Drugi nacin za racunanje sume parnih i neparnih ( bez akumulatora)

sumaPN1(0,0,0).
sumaPN1(N,SP,SN):-N>0,N mod 2 =:= 0, N1 is N-1, sumaPN1(N1,SP1,SN),SP is SP1+N.
sumaPN1(N,SP,SN):-N>0,N mod 2 =\= 0, N1 is N-1, sumaPN1(N1,SP,SN1),SN is SN1+N.

% k-ta cifra gledano s desna u levo
ktaDL(N,1,X):-N>0, X is N mod 10.
ktaDL(N,K,X):-N>0, N1 is N // 10,K1 is K-1, ktaDL(N1,K1,X).

%k-ta cifra gledano s leva u desno
ktaLD(N,K,X):-obrni(N,N1),ktaDL(N1,K,X).

% LISTE

%element liste
elem(X,[X|_]).
elem(X,[_|Y]):-elem(X,Y).

%dodaj na pocetak liste

dodajPoc(X,L,[X|L]).

dodajKraj(X,[],[X]).
dodajKraj(X,[L|Rep],[L|Rep1]):-dodajKraj(X,Rep,Rep1).
%suprotan

listaSuprotni(X,X1):-listaSup(X,X,X1).
listaSup([],_,[]).
listaSup([X|R],Lista,[X|Rep]):- X1 is -X,not(elem(X1,Lista)),listaSup(R,Lista,Rep).
listaSup([X|R],Lista,Rep):- X1 is -X, elem(X1,Lista) ,listaSup(R,Lista,Rep).

%neopadajuci prefiks i ostatak

lista([],[],[]).
lista([X,Y|Rep],[X|NeopRep],Ost):-X=<Y,lista([Y|Rep],NeopRep,Ost).
lista([X,Y|Rep],[],[Y|Rep]):-X>Y.