/*
 * Copyright 2011 Steven Gribble
 *
 *  This file is the solution to an exercise problem posed during
 *  one of the UW CSE 333 lectures (333exercises).
 *
 *  333exercises 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.
 *
 *  333exercises 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 333exercises.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _GRAPHOPS_H_
#define _GRAPHOPS_H_

#include "ll.h"

// We represent a collaboration graph as a linked list of scientists.
// For each scientist in the list, we store a Collab; a Collab
// contains the string name of the scientist, as well a linked list
// of collaborators.  (Each node in the linked list ofcollaborators
// contains the string name of the collaborators.)
//
// Pictorially...
//
//       A --> B --> C --> D
//       |     |     |     |
//       B     A     A     A
//       |           |     |
//       C           D     C
//       |
//       D
typedef struct CollabSt {
  char *scientist;
  Node *collaborators;
} Collab;

// This is the main linked list of scientist Collab structs.
extern Node *collabgraph;

// Loops through the collaboration graph, looking for the
// scientist with the given name.  If found, returns the
// head of the linked list of collaborators.  If not found,
// returns NULL.
Node *GetCollaboratorList(char *scientist);

// Tests to see whether the given collaborator is already
// listed in the collaborator list for scientist "scientist".
// If so, returns 1.  If either the scientist couldn't be
// found, or the collaborator isn't listed for the scientist,
// returns 0.
int TestIfCollaborator(char *scientist, char *collaborator);

// Adds the (scientist --> collaborator) pair to the
// collaboration graph, making a copy of both strings.
void AddCollaboration(char *scientist, char *collaborator);

#endif  // _READLINE_FROM_FILE_H_