annotate toolboxes/FullBNT-1.0.7/graph/topological_sort.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
parents
children
rev   line source
wolffd@0 1 function order = topological_sort(A)
wolffd@0 2 % TOPOLOGICAL_SORT Return the nodes in topological order (parents before children).
wolffd@0 3 % order = topological_sort(adj_mat)
wolffd@0 4
wolffd@0 5 n = length(A);
wolffd@0 6 indeg = zeros(1,n);
wolffd@0 7 zero_indeg = []; % a stack of nodes with no parents
wolffd@0 8 for i=1:n
wolffd@0 9 indeg(i) = length(parents(A,i));
wolffd@0 10 if indeg(i)==0
wolffd@0 11 zero_indeg = [i zero_indeg];
wolffd@0 12 end
wolffd@0 13 end
wolffd@0 14
wolffd@0 15 t=1;
wolffd@0 16 order = zeros(1,n);
wolffd@0 17 while ~isempty(zero_indeg)
wolffd@0 18 v = zero_indeg(1); % pop v
wolffd@0 19 zero_indeg = zero_indeg(2:end);
wolffd@0 20 order(t) = v;
wolffd@0 21 t = t + 1;
wolffd@0 22 cs = children(A, v);
wolffd@0 23 for j=1:length(cs)
wolffd@0 24 c = cs(j);
wolffd@0 25 indeg(c) = indeg(c) - 1;
wolffd@0 26 if indeg(c) == 0
wolffd@0 27 zero_indeg = [c zero_indeg]; % push c
wolffd@0 28 end
wolffd@0 29 end
wolffd@0 30 end