%input :- [reachin1000].    % one way of reading input facts
:- include(reachin1000).   % 2nd way of reading input facts

% Way 1
%reach(X) :- source(X).
%reach(Y) :- reach(X), edge(X,Y).
% Way 2
%reach(Y) :- reach(X), edge(X,Y).
%reach(X) :- source(X).
% Way 3
%reach(X) :- source(X).
%reach(Y) :- edge(X,Y), reach(X).
% Way 4
reach(Y) :- edge(X,Y), reach(X).
reach(X) :- source(X).

:- table reach/1.

printReach :- reach(X), write(X), write(' '), fail.
printReach.

%timeReach :- cputime(X), input, printReach, cputime(Y), T is Y-X, write(T).
%timeReach :- input, cputime(X), printReach, cputime(Y), T is Y-X, write(T).
timeReach :- cputime(X), printReach, cputime(Y), T is Y-X, write(T).

source(3).