fork(2) download
copy 
  1. :- set_prolog_flag(verbose,silent).
  2. :- prompt(_, '').
  3. :- use_module(library(readutil)).
  4.  
  5. main:-
  6. 	process,
  7. 	halt.
  8.  
  9. positions(X, L, R) :- positions(X, L, R, 1).
  10.  
  11. positions(_, [], [], _).
  12. positions(X, [X|T], [I|R], I) :- plus(I, 1, N), positions(X, T, R, N).
  13. positions(X, [Y|T], R, I) :- X \= Y, plus(I, 1, N), positions(X, T, R, N).
  14.  
  15.  
  16. process:-
  17. 	positions(3, [0,1,2,3,4,3,2,3,4,5,6,3,2,1], R), write(R), nl,
  18. 	true.
  19.  
  20. :- main.
Success #stdin #stdout 0.02s 7480KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
[4,6,8,12]
https://ideone.com/ZnV80S
language:
Prolog (swi 7.6.4)
created:
9 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!