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Diffstat (limited to '')
-rw-r--r-- | src/2geom/utils.cpp | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/src/2geom/utils.cpp b/src/2geom/utils.cpp new file mode 100644 index 0000000..83d93cc --- /dev/null +++ b/src/2geom/utils.cpp @@ -0,0 +1,86 @@ +/** Various utility functions. + * + * Copyright 2008 Marco Cecchetti <mrcekets at gmail.com> + * Copyright 2007 Johan Engelen <goejendaagh@zonnet.nl> + * Copyright 2006 Michael G. Sloan <mgsloan@gmail.com> + * + * This library is free software; you can redistribute it and/or + * modify it either under the terms of the GNU Lesser General Public + * License version 2.1 as published by the Free Software Foundation + * (the "LGPL") or, at your option, under the terms of the Mozilla + * Public License Version 1.1 (the "MPL"). If you do not alter this + * notice, a recipient may use your version of this file under either + * the MPL or the LGPL. + * + * You should have received a copy of the LGPL along with this library + * in the file COPYING-LGPL-2.1; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * You should have received a copy of the MPL along with this library + * in the file COPYING-MPL-1.1 + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY + * OF ANY KIND, either express or implied. See the LGPL or the MPL for + * the specific language governing rights and limitations. + * + */ + + +#include <2geom/utils.h> + + +namespace Geom +{ + +// return a vector that contains all the binomial coefficients of degree n +void binomial_coefficients(std::vector<size_t>& bc, std::size_t n) +{ + size_t s = n+1; + bc.clear(); + bc.resize(s); + bc[0] = 1; + for (size_t i = 1; i < n; ++i) + { + size_t k = i >> 1; + if (i & 1u) + { + bc[k+1] = bc[k] << 1; + } + for (size_t j = k; j > 0; --j) + { + bc[j] += bc[j-1]; + } + } + s >>= 1; + for (size_t i = 0; i < s; ++i) + { + bc[n-i] = bc[i]; + } +} + +} // end namespace Geom + + + + + + + + + + + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : |