% A = perms(v)
% generate all permutations of v, one row per permutation.
% The resulting A has size n x n, where n is the length of v
% so keep v small
function A = perms(v)
n = length(v);
if (n == 1)
A = v;
else
B = perms(v(1:n-1));
Bidx = 1:size(B,1);
A = v(n) * ones(prod(2:n), n);
A (Bidx, 1:n-1) = B;
k = size(B,1);
for i = n-1:-1:2
A (k+Bidx, 1:i-1) = B(Bidx, 1:i-1);
A (k+Bidx, i+1:n) = B(Bidx, i:n-1);
k = k + size(B,1);
end
A (k+Bidx, 2:n) = B;
end
% Copyright (C) 2001 Paul Kienzle
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA