hihih123
0
I am a beginner at Prolog so I got this piece of code but I don't understand why it doesn't work
max([Max],Max).
max([H1,H2|T],Max):- H1 > H2, max([H1|T],Max).
max([H1,H2|T],Max):- H1 < H2, max([H2|T],Max).
pozitia([X|_], X, 1).
pozitia([_|Y], X, I) :- pozitia(Y, X, I2), I is I2 + 1.
questions
max([1,2,3,4,5,7,2],X).
pozitia([1,2,3,4,5,3,2,1,1,2,3,4], 4, Pozitia).
The error I got is Syntax error: Operator expected.
I don't understand why!
Syntactically, if you replace question with question. (add a dot), your code will work, prolog could not figure out anything about question whether it is a fact or a rule.
Logically, you have to comment out the last 3 lines!
max([Max],Max).
max([H1,H2|T],Max):- H1 > H2, max([H1|T],Max).
max([H1,H2|T],Max):- H1 < H2, max([H2|T],Max).
pozitia([X|_], X, 1).
pozitia([_|Y], X, I) :- pozitia(Y, X, I2), I is I2 + 1.
% questions
% max([1,2,3,4,5,7,2],X).
% pozitia([1,2,3,4,5,3,2,1,1,2,3,4], 4, Pozitia).
These are some queries to test max and pozitia rules.
