YoungTab.cc

/*

Cadabra: a field-theory motivated computer algebra system.
Copyright (C) 2001-2011  Kasper Peeters <kasper.peeters@aei.mpg.de>

	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 3 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, see <http://www.gnu.org/licenses/>.

*/

#include "YoungTab.hh"
#include <cassert>

namespace yngtab {

	tableau_base::tableau_base()
		: multiplicity(1), selfdual_column(0)
		{
		}

	tableau_base::~tableau_base()
		{
		}

	tableau::~tableau()
		{
		}

	tableau::tableau()
		: tableau_base()
		{
		}

	tableau::tableau(const tableau& other)
		{
		rows=other.rows;
		}

	void tableau_base::add_row(unsigned int row_size)
		{
		assert(row_size>0);
		unsigned int row=number_of_rows();
		for(unsigned int i=0; i<row_size; ++i)
			add_box(row);
		}

	yngint_t tableau_base::dimension(unsigned int dim) const
		{
		yngint_t ret=1;
		for(unsigned int r=0; r<number_of_rows(); ++r) {
			unsigned int backup=dim;
			for(unsigned int c=0; c<row_size(r); ++c)
				ret*=(dim++);
			dim=backup-1;
			}
		assert(ret%hook_length_prod()==0);
		ret/=hook_length_prod();
		return ret;
		}

	unsigned int tableau_base::column_size(unsigned int c) const
		{
		unsigned int r=0;
		while(r<number_of_rows()) {
			if(row_size(r)-1<c)
				break;
			++r;
			}
		return r;
		}

	unsigned long tableau_base::hook_length(unsigned int row, unsigned int col) const
		{
		assert(row<number_of_rows());
		assert(col<row_size(row));
		unsigned long hook=row_size(row)-col;
		for(unsigned int i=row+1; i<number_of_rows() && col<row_size(i); ++i)
			++hook;
		return hook;
		}

	yngint_t tableau_base::hook_length_prod() const
		{
		yngint_t hook=1;
		for(unsigned int i=0; i<number_of_rows(); ++i)
			for(unsigned int j=0; j<row_size(i); ++j)
				hook*=hook_length(i,j);
		return hook;
		}

	void tableau::add_box(unsigned int rownum)
		{
		if(rownum>=rows.size()) {
			unsigned int prevsize=rows.size();
			rows.resize(rownum+1);
			for(unsigned int i=prevsize; i<rows.size(); ++i)
				rows[i]=0;
			}
		++rows[rownum];
		}

	void tableau::remove_box(unsigned int rownum)
		{
		assert(rownum<rows.size());
		assert(rows[rownum]>0);
		if((--rows[rownum])==0)
			rows.pop_back();
		}

	unsigned int tableau::number_of_rows() const
		{
		return rows.size();
		}

	unsigned int tableau::row_size(unsigned int num) const
		{
		assert(num<rows.size());
		return rows[num];
		}

	void tableau::clear()
		{
		rows.clear();
		}

	tableau& tableau::operator=(const tableau& other)
		{
		rows=other.rows;
		return (*this);
		}

	std::ostream& operator<<(std::ostream& str, const tableau& tab)
		{
		for(unsigned int i=0; i<tab.number_of_rows(); ++i) {
			for(unsigned int j=0; j<tab.row_size(i); ++j) {
				//			str << "|x|";
				str << "x";
				}
			if(i==0) str << "  " << tab.dimension(10) << " " << tab.hook_length_prod();
			if(i!=tab.number_of_rows()-1)
				str << std::endl;
			}
		return str;
		}

	//bool legal_box(const std::vector<std::pair<int,int> >& prev,
	//					const std::vector<std::pair<int,int> >& ths,
	//					int colpos, int rowpos)
	//	{
	//	// Note the initial condition: upon startup, the prev vector contains as many -1,-1
	//   // pairs as boxes in the first row of tableau 2. So 'prevabove' will initially evaluate
	//	// to this number.
	//
	//	int prevabove=0; // number of boxes of the previous row added above the candidate position
	//	int thisabove=0; // number of boxes of the current  row added above the candidate position
	//	for(unsigned int i=0; i<prev.size(); ++i) {
	//		if(prev[i].second<rowpos)
	//			++prevabove;
	//		}
	//	for(unsigned int i=0; i<ths.size(); ++i) {
	//		if(ths[i].first==colpos) return false; // would imply anti-symmetrisation of symmetrised boxes
	//		if(ths[i].second<rowpos)
	//			++thisabove;
	//		}
	//	if(prevabove>thisabove) return true;
	//	return false;
	//	}

#ifndef __CYGWIN__
#ifndef _WIN32
	template<>
	void add_box(tableau& tab1, unsigned int row1,
	             const tableau&, unsigned int, unsigned int)
		{
		tab1.add_box(row1);
		}
#endif
#endif

	};