text: /*
   * CXSPARSE: a Concise Sparse Matrix package - Extended.
   * Copyright (c) 2006-2009, Timothy A. Davis.
   * http://www.cise.ufl.edu/research/sparse/CXSparse
   * 
   * CXSparse is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   * 
   * CXSparse 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
   * Lesser General Public License for more details.
   * 
   * You should have received a copy of the GNU Lesser General Public
   * License along with this Module; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "cs.h"
  /* xi [top...n-1] = nodes reachable from graph of G*P' via nodes in B(:,k).
   * xi [n...2n-1] used as workspace */
  CS_INT cs_reach (cs *G, const cs *B, CS_INT k, CS_INT *xi, const CS_INT *pinv)
  {
      CS_INT p, n, top, *Bp, *Bi, *Gp ;
      if (!CS_CSC (G) || !CS_CSC (B) || !xi) return (-1) ;    /* check inputs */
      n = G->n ; Bp = B->p ; Bi = B->i ; Gp = G->p ;
      top = n ;
      for (p = Bp [k] ; p < Bp [k+1] ; p++)
      {
          if (!CS_MARKED (Gp, Bi [p]))    /* start a dfs at unmarked node i */
          {
              top = cs_dfs (Bi [p], G, top, xi, xi+n, pinv) ;
          }
      }
      for (p = top ; p < n ; p++) CS_MARK (Gp, xi [p]) ;  /* restore G */
      return (top) ;
  }
  