list_operations.h

/*
 * Normaliz
 * Copyright (C) 2007-2014  Winfried Bruns, Bogdan Ichim, Christof Soeger
 * 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/>.
 *
 * As an exception, when this program is distributed through (i) the App Store
 * by Apple Inc.; (ii) the Mac App Store by Apple Inc.; or (iii) Google Play
 * by Google Inc., then that store may impose any digital rights management,
 * device limits and/or redistribution restrictions that are required by its
 * terms of service.
 */

//---------------------------------------------------------------------------
#ifndef LIST_OPERATIONS_H
#define LIST_OPERATIONS_H


//---------------------------------------------------------------------------
                  
#include <vector>
#include <list>
#include <ostream>

#include "libnormaliz/libnormaliz.h"
#include "libnormaliz/simplex.h"

namespace libnormaliz {
using std::vector;
using std::list;

//---------------------------------------------------------------------------
//                          Data access
//---------------------------------------------------------------------------

template <typename T>
std::ostream& operator<< (std::ostream& out, const list<T>& l) {
    typename list<T>::const_iterator i;
    for (i =l.begin(); i != l.end(); i++) {
        out << *i << " ";
    }
    out << std::endl;
    return out;
}

//---------------------------------------------------------------------------
//                         List operations
//---------------------------------------------------------------------------

template<typename Integer>
 vector<Integer> l_multiplication(const list< vector<Integer> >& l,const vector<Integer>& v);
 //the list shall contain only vectors of size=v.size(). Returns a vector
 //containing all the scalar products  (we see l as as matrix and return l*v).
template<typename Integer>
 list< vector<Integer> > l_list_x_matrix(const list< vector<Integer> >& l,const Matrix<Integer>& M);
 //the list shall contain only vectors of size=M.nr_of_rows(). Returns a list
 //containing the product  (we see l as as matrix and return l*M).
template<typename Integer>
 void  l_cut(list<  vector<Integer> >& l,int size );
 //cuts all the vectors in l to a given size.
template<typename Integer>
 void  l_cut_front(list<  vector<Integer> >& l,int size );
 //cuts all the vectors in l to a given size, maintaining the back
 
//---------------------------------------------------------------------------

template<typename T>
void random_order(list<T>& LL){
    vector<typename list<T>::iterator > list_order;
    size_t nrLL=LL.size();
    list_order.reserve(nrLL);
    typename  list<T>::iterator p=LL.begin();
    for(size_t k=0;k<nrLL;++k,++p){
        list_order.push_back(p);
    }
    for(size_t k=0;k<10*nrLL;++k){
        swap(list_order[rand()%nrLL],list_order[rand()%nrLL]);
    }
    list<T> new_order;
    for(size_t k=0;k<nrLL;++k){
        new_order.push_back(*list_order[k]);
    }
    LL.clear();
    LL.splice(LL.begin(),new_order);

}

//---------------------------------------------------------------------------

template<typename T>
void random_order(list<T>& LL,typename list<T>::iterator from, typename  list<T>::iterator to ){

    list<T> MM;
    MM.splice(MM.begin(),LL,from,to);
    random_order(MM);
    LL.splice(LL.begin(),MM);
}


}

//---------------------------------------------------------------------------
#endif
//---------------------------------------------------------------------------