Line data    Source code

       1              : /*
       2              :  * Copyright (c) 2013-2015:  G-CSC, Goethe University Frankfurt
       3              :  * Author: Martin Rupp
       4              :  * 
       5              :  * This file is part of UG4.
       6              :  * 
       7              :  * UG4 is free software: you can redistribute it and/or modify it under the
       8              :  * terms of the GNU Lesser General Public License version 3 (as published by the
       9              :  * Free Software Foundation) with the following additional attribution
      10              :  * requirements (according to LGPL/GPL v3 §7):
      11              :  * 
      12              :  * (1) The following notice must be displayed in the Appropriate Legal Notices
      13              :  * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
      14              :  * 
      15              :  * (2) The following notice must be displayed at a prominent place in the
      16              :  * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
      17              :  * 
      18              :  * (3) The following bibliography is recommended for citation and must be
      19              :  * preserved in all covered files:
      20              :  * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
      21              :  *   parallel geometric multigrid solver on hierarchically distributed grids.
      22              :  *   Computing and visualization in science 16, 4 (2013), 151-164"
      23              :  * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
      24              :  *   flexible software system for simulating pde based models on high performance
      25              :  *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
      26              :  * 
      27              :  * This program is distributed in the hope that it will be useful,
      28              :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      29              :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
      30              :  * GNU Lesser General Public License for more details.
      31              :  */
      32              : 
      33              : #include "permutation_util.h"
      34              : 
      35              : 
      36              : namespace ug{
      37              : 
      38              : 
      39            0 : bool GetInversePermutation(const std::vector<size_t> &perm, std::vector<size_t> &invPerm)
      40              : {
      41            0 :         invPerm.resize(perm.size());
      42              :         bool bId = true;
      43            0 :         for(size_t i=0; i<perm.size(); i++) invPerm[i] = (size_t) (-1);
      44              : 
      45            0 :         for(size_t i=0; i<perm.size(); i++)
      46              :         {
      47            0 :                 UG_COND_THROW(invPerm[perm[i]] != (size_t) (-1), "not a bijective permutation "
      48              :                         "(double mapping to index " << perm[i] << " by indices " << invPerm[perm[i]] << " and " << i << ")!");
      49            0 :                 bId = bId && perm[i] == i;
      50            0 :                 invPerm[perm[i]] = i;
      51              :         }
      52            0 :         return bId;
      53              : }
      54              : 
      55              : 
      56              : }