# HG changeset patch
# User IBBoard <dev@ibboard.co.uk>
# Date 1507387432 -3600
# Node ID b4f994693f7b0c2fa77a3c23735bb9954e56379a
# Parent  8906b5a4517fe658c55c62ea93ebdff9d61f1646
Fix condition check that was letting it backtrack to build a different set of rows

diff -r 8906b5a4517f -r b4f994693f7b 3-Prolog/day3-sudoku.pl
--- a/3-Prolog/day3-sudoku.pl	Sat Oct 07 15:07:34 2017 +0100
+++ b/3-Prolog/day3-sudoku.pl	Sat Oct 07 15:43:52 2017 +0100
@@ -38,7 +38,7 @@
 nth_from_list(Start, N, Input, Output) :- nth_from_list(N, Start, 1, Input, Output).
 nth_from_list(N, Next, Pos, [Head|TailIn], [Head|TailOut]) :- Pos == Next, NewNext is Next + N, NewPos is Pos + 1,
     nth_from_list(N, NewNext, NewPos, TailIn, TailOut).
-nth_from_list(N, Next, Pos, [_|TailIn], Output) :- NewPos is Pos + 1, nth_from_list(N, Next, NewPos, TailIn, Output).
+nth_from_list(N, Next, Pos, [_|TailIn], Output) :- Pos < Next, NewPos is Pos + 1, nth_from_list(N, Next, NewPos, TailIn, Output).
 nth_from_list(_, _, _, [], []).
 
 cols(Board, ColLength, Cols) :- cols(Board, ColLength, 1, Cols).